神华煤直接液化残渣超临界溶剂萃取研究

利用甲苯、苯和乙醇三种溶剂在反应釜中对神华煤直接液化残渣进行了超临界溶剂萃取,考察了压力、温度、萃取时间、溶剂/残渣比等对萃取产物收率和重质液体萃取组成的影响。结果表明,以甲苯为溶剂进行萃取时,萃取时间对重质液体产率及HS和A收率的影响不大,而温度、压力以及溶剂/残渣质量比都会影响萃取产物的产率及组成。溶剂超临界萃取过程中,有其他组分向HS组分转化,提高了HS的收率。三种溶剂中,苯显示了和甲苯相似的萃取性能,而乙醇的萃取性能相比苯和甲苯则较差,但乙醇萃取得到的重质液体中轻质组分含量高于苯和甲苯。萃取过程中,残渣中的灰分和硫分主要富集至萃取残渣中。     

煤直接液化残渣及其萃取产物的热重分析

利用热天平考察了神华和胜利两种典型中国煤直接液化残渣及其萃取产物的失重曲线。实验表明,神华残渣和胜利残渣的轻质组分含量相近,其失重率也相近,但轻质组分组成不同使得失重过程并不一致 。升温速率增加,热解最大失重速率增加,最大失重速率温度升高。以残渣各组分失重曲线拟合得到的残渣失重曲线可近似表示残渣的失重曲线。动力学分析表明,由实验数据拟合的活化能和指前因子计算得到的失重曲线,与实际实验得到的失重曲线较为一致。液化残渣在低温区失重率很高,而且这部分失重产物可以通过溶剂萃取的方式得到。     

神华煤直接液化残渣萃取残渣焦气化动力学研究

在热天平上分别考察了甲苯、苯及乙醇萃取液化残渣热解焦在水蒸气和CO2气氛下的气化动力学,并对比了液化残渣热解焦在相同条件下的气化反应性。结果表明,温度是影响残渣焦气化反应速率的重要因素;超临界溶剂对残渣的萃取使得残渣焦中碳基质的有序度有所降低,并在一定程度上增加了残渣焦的孔结构,因此,提高了残渣焦的气化反应性;残渣焦孔结构不发达,可以使用化学反应控制未反应收缩核模型预测残渣焦的气化反应过程。     

煤直接液化残渣的热解特性研究

利用热重、固定床热解和红外光谱技术研究煤直接液化残渣的热解特性及热解产物分布、组成和性质,考察了热解回收油品的适用条件。结果表明,450℃~500℃下神华煤液化残渣(SHR)和胜利煤液化残渣(SLR)热解油产率分别约为32%和20%,450℃后升高温度对油产率影响不大,但会使热解油中沥青烯(A)含量增加。SHR的热解油主要是己烷可溶物组分(HS),与SHR中HS结构相似。但SLR的热解油中A组分含量接近50%。SHR中的HS组分在热解时的聚合并不明显;而SLR中的HS组分在热解过程中伴随明显的聚合,导致热解油中含有大量的沥青烯。在400℃~500℃,两种残渣中A均有向热解油转化的趋势,而且SLR中A组分表现出了较大的逸出能力。但从热解产物组成分布分析,A的逸出还是少量的,一部分分解产生油品,一部分与前沥青烯和四氢呋喃不溶物(THFIS)一起形成了半焦。     

煤直接液化残渣对道路沥青改性作用的初步评价

现代交通具有轴载重、通量大和轮胎内压高的特点,因此,对公路路面提出了更高的要求。沥青是路面材料的重要组分之一,起黏结剂的作用,但由于沥青自身的温度敏感性,直接来自原油的道路沥青或重交通道路沥青自身不能满足要求。随着四季自然条件的变化,沥青变软或变硬,以致老化变脆,使路面发生损坏如车辙、开裂、剥离等。为了改善道路沥青路面的使用性能,使用改性沥青是解决这一问题的重要方法。改性沥青是在常规道路沥青中添加改性剂后的均匀沥青混合物。目前,大部分的高速公路的铺设均使用改性沥青。     

煤直接液化残渣溶剂萃取组分的热解行为研究

利用热重技术和固定床热解/在线质谱检测技术研究了残渣萃取组分重质油(HS)、沥青烯(A)、前沥青烯(PA)和四氢呋喃不溶物(THFIS)的热解特性,并尝试探讨了各萃取组分的热解行为与加氢行为之间的关系。研究结果表明,残渣中各萃取组分的加氢转化能力与其热分解能力有关。四种组分在SHR加氢液化产生的正协同作用的原因,在于各萃取组分之间的相互作用导致了HS和A族组分中的某些低温挥发组分,在较低温度区间不挥发逸出,而在较高温度区间裂解,迎合了加氢液化对自由基碎片的需求。但PA的存在有利于缩聚反应的发生,可促进裂解产物的再聚合,从而对加氢液化产生不利影响。     

煤直接液化残渣制备水渣浆成浆性的研究

以煤直接液化残渣制备了水渣浆，考察了粒径分布、搅拌时间、分散剂的用量及种类对水渣浆性质的影响。根据实验确定了制备水渣浆的最佳工艺参数：Alfred粒径分布模型（d_280~154μm、d_154~74μm、d_<74μm 质量分数分别为14%、16%、70%），搅拌时间20 min，分散剂加入量为干渣基1.0%。实验结果表明，液化残渣制备水渣浆的定黏质量分数分别为73.5%（NSF）和71.0%（SL）。分散剂萘磺酸盐甲醛缩合物（NSF）的分散降黏效果优于改性碱木质素磺酸钠（SL），而水渣浆的流变性，分散剂SL要优于分散剂NSF。     

神华煤直接液化残渣水蒸气和CO_2气化反应性研究

分别对神华煤和神华煤直接液化残渣的水蒸气和CO2气化反应性进行了研究。结果表明,水蒸气气化反应中,煤半焦的反应性强于残渣半焦;CO2气化反应中,残渣半焦的反应性强于煤半焦。这主要是影响煤和残渣水蒸气和CO2气化反应性的关键因素不同。水蒸气气化反应受煤化程度的影响较大,而CO2气化反应受煤化程度的影响较小,受矿物质催化作用的影响大。     

煤直接液化残渣焦CO2气化反应的研究

比较了流化床条件下神华煤及其直接液化残渣焦在CO2气氛中的气化反应性,考察了添加液化催化剂、脱除矿物质以及脱除重质油对煤直接液化残渣气化反应的影响规律。结果表明,残渣焦的气化反应性比原煤焦好,残渣焦在1000℃和1100℃的气化反应性指数为0.135和0.290,而原煤焦的则为0.118和0.200。脱灰后残渣焦气化反应性低于脱灰后的煤焦,说明直接液化反应后剩余的难液化物质的气化反应性低于煤焦;未经脱灰处理的残渣焦气化反应性高于煤焦,反映了液化过程中富集的矿物质及铁系催化剂的催化气化活性。脱除残渣中的重质油会降低残渣焦的气化反应性。     

神华煤直接液化残渣热解特性研究

通过热重分析技术考察了神华煤直接液化残渣的热解特性。结果表明,和煤热解相比,在相同条件下残渣热解具有更大的失重率和失重速率。残渣热失重分为三个阶段,在173℃以前为残渣热解第一阶段;从173℃～510℃是残渣热解第二阶段,此阶段为残渣的主要失重阶段;510℃以后是残渣热解的第三阶段,在这个阶段残渣继续失重,此阶段的失重是由于残渣的二次分解和残渣中的矿物质分解造成的。通过比较脱油前后残渣热失重曲线发现,残渣主要失重是由于残渣中重质油、沥青烯以及前沥青烯的热解以及挥发造成的。通过脱灰残渣的热解发现,与原残渣相比,脱灰后残渣的失重量变小,矿物质的分解和残渣中有机组分的缩聚是温度高于649℃以后残渣失重的主要原因。由热解特征参数看出,脱油残渣的初始热解温度、最大失重温度以及剧烈热解终温均高于原煤,说明和原煤相比,脱油后残渣中惰性组分不易热解。与原煤和四氢呋喃脱油渣相比,残渣具有最大的失重速率,这是由于残渣中含有大量重质油、沥青烯以及前沥青烯造成的。     

Supercritical Fluid Extraction of Saponins from Ginseng

Introduction Ginseng（ Panax ginseng C. A. Meyer, Araliaceae） is one of the most valuable Chinese crude drugs and has been used widely for over 2000 years. Studies have demonstrated that ginseng can act on the central nervous system, the cardiovascular system and the endocrine system; it can enhance immune function and metabolism; it possesses a biomodulation action, anticancer effect, anti-stress and anti-ageing activities, and so on.     

Isolation and Extraction of Total Flavonoids from Epimedium Koreanum Nakai by Supercritical Fluid Extraction

In the present paper is reported the metnocl for the isolation and extraction of total flavonoids of Epimedium Koreanum Nateai by means of supercritical fluid extraction(SFE). By examining pressure, temperature, amounts of modifier and extraction time, the optimized condition of SFE is confirmed as 30 MPa and 60℃, with 70% ethanol as the modifier. The samples were statically extracted for 30 min, followed bydynamic extraction for 120 min at a flow rate of 6 mL/min. The quantitative analysis of total flavonoids was performed by UV-Vis spectrophotometry. Compared with the conventional method, the SFE method is more efficient, more rapid and more friendly environmentally.     

Supercritical Fluid Extraction of Total Flavonoids from Leaves of Acanthopanax Senticosus Harms

Introduction The herbal plant Acanthopanax Senticosus Harms[1,2] is natural herb of Changbaishan in Jilin Province of China, which belongs to the Araliaceae family. As the ingredients of folk medicine, it has long been used to treat a variety of human diseases, such as cerebrovascular disease, diabetes, tumor, isochemic heart diseases, hypertension, rheumatic arthritis,etc.[2,3].     

Statistical Analysis of Liquid Trapping Efficiencies of Fat-Soluble Vitamins Following Supercritical Fluid Extraction

A series of four complete factorial experiments were performed to determine the major parameters affecting the trapping efficiencies of fat-soluble vitamins after supercritical fluid extraction. The parameters varied were the collection solvent, extraction flow rate, collection temperature, restrictor temperature, and collection pressurization. The identity of the collection solvent was found to have the most profound effect. The viscosity and surface tension of the collection solvent appeared to have great significance.     

Supercritical Fluid Extraction Acanthopanax of Total Flavonoids from Leaves of Senticosus Harms

The herbal plant Acanthopanax Senticosus Harms is natural herb of Changbaishan in Jilin Province of China, which belongs to the Araliaceae family. As the ingredients of folk medicine, it has long been used to treat a variety of human diseases, such as cerebrovascular disease, diabetes, tumor, isochemic heart diseases, hypertension, rheumatic arthritis, etc. E2,33. Flavonoids, a class of constituent compounds, which have a broad distribution in the nature and are found in Acanthopanax Senticosus Harms, have gained particular attention. A number of studies have shown that flavonoid compounds have wide biological activities, such as anti-aging, anticancer, anti-HIV,     

Modifier and Additive Effects in the Supercritical Fluid Extraction of Pseudoephedrine Hydrochloride from Spiked-Sand and Suphedrine Tablets

The effect of modifier and additive composition upon pseudoephedrine recovery from spiked-sand and Suphedrine tablets was examined. Recovery was shown to be dependent on CO₂ density as well as on the addition of an ion pairing agent to the matrix. The presence of methanol in the extraction vessel prior to SFE was shown to play a significant role in the ion-pair extraction process. Recovery was also shown to be a function of ion-pairing reagent composition and concentration. The most successful recovery was obtained in the presence of 1-heptanesulfonic acid (HSA), sodium salt in methanol at a 5:1 molar ratio (reagent to drug). The increased extractability in the presence of ion-pairing reagent was attributed to reduced analyte polarity and analyte-matrix displacement. Alternatively, a matrix-spiked mixture of methanol and 1% water by itself was just as effective as a matrix-spiked mixture of methanol and HSA for attaining efficient extraction. Several in-cell (e. g. to the matrix) and in-line (e. g. to the fluid) modifiers were examined for the extraction of pseudoephedrine from Suphedrine tablets. The greatest pseudoephedrine recovery from Suphedrine tablets of 82% (7.0%) was achieved with 10% (l% H₂O) methanol-modified CO₂ in the presence of 400 μL of methanol (l% H₂O). Finally AgCl tests and infrared analyses were performed on two tablet extracts. It was confirmed that even in the absence of any in-cell modifier, a small fraction of pseudoephedrine hydrochloride could be extracted.     

小白菜中残留虫酰肼的超临界流体萃取条件的研究

将超临界流体萃取(supercritical fluid extraction,SFE)技术与高效液相色谱分析相结合,建立了特异性杀虫剂虫酰肼的萃取分离方法。SFE对虫酰肼的萃取条件:压力48.3 MPa(7000 psi),温度60 ℃,静态萃取时间20 min,CO2体积10 mL,改性剂甲醇添加量0.04 mL/g,丙酮为收集溶剂。在此条件下,SFE对虫酰肼的萃取率为100.75%,所得样品可直接用于高效液相色谱分析。色谱条件：紫外-二极管阵列检测器(检测波长为245 nm),C18键合色谱柱,乙腈     

Comparison of Supercritical Fluid Extraction with Solvent Sonication for Chemical Warfare Agent Determination in Alkyd Painted Plates

Supercritical fluid extraction (SFE) of alkyl alkylphosphonofluoridates and dialkyl alkylphosphonates from painted plates was investigated. It was found that SFE recoveries compared favorably with conventional solvent sonication results. Stability studies of the samples were carried out over a period of two months. This investigation showed that the concentration of phosphonofluoridates decreased over a long period.     

Trapping Efficiencies of Various Adsorbents in Supercritical Fluid Extraction with Modified Carbon Dioxide

One way of collecting extracted analytes after a supercritical fluid extraction (SFE) is to pass the depressurized fluid through a trap composed of a solid adsorbent. The influence of the adsorbent nature on the trap efficiency has been studied. First, the retention factors of each compound of a polarity test mix (tetracosane, naphthalene, fluoranthene, acetophenone, N,N-dimethylaniline, 2-naphthol, decanoic acid) have been determined on five high specific area (greater than 800 m²/g) polymeric phases by supercritical fluid chromatography (SFC). The comparison of this values with those obtained on octadecyl silica (ODS) showed that polymeric phases have the greatest retention power. After that, the efficiency of a solid trap filled with the greatest retention power polymeric adsorbent was evaluated by using pure carbon dioxide and 2.5%, 5%, 10%, and 20% methanol-modified carbon dioxide. As expected, this trap permitted a quantitative collection of all the former compounds even when a content as high as 10% of methanol was implemented. A solid trap filled with ODS adsorbent allowed quantitative collection of all the compounds only at a methanol content lower than 2.5%.     

超临界流体萃取技术在乏燃料后处理中的应用

未来的动力堆乏燃料具有高燃耗、高钚含量和燃料类型多样等特点,采用传统的溶剂萃取法流程处理将面临很大挑战,而干法后处理技术虽经多年研究,仍有许多问题有待解决,因此有必要探索新的非水法后处理技术。将超临界流体萃取应用于乏燃料后处理可以简化后处理流程,大量减少二次废液的产生,具有很好的发展前景。本文综述了超临界流体萃取技术在乏燃料后处理中的应用研究,对基于超临界萃取技术的乏燃料后处理概念流程进行了评述。对将电化学插层法与超临界流体萃取技术结合,用于处理高温气冷堆乏燃料的可行性进行了讨论。