Theoretical Studies on Critical Properties of Binary System with Supercritical Carbon Dioxide

A new expression of mixing rule is suggested according to the Mayson‘s mixing rule in this paper,which adopts the Redlich-Kwong cubic equation of state and the modifed Chueh-Prausnitz method to calculate the experiment critical points of six binary mixtures CO2 toluene,CO2 cyclohexane,CO2 n-butanal,CO2 i-butanal,CO2 methanol,CO2 ethanol.The coefficients of interaction parameter in the expression of mixing rule were optimized from experimental data.The calculated results of critical temperature and critical pressure meet the experiment data well.The maximum relative errore of temperature and pressure between the calculation results and experiment data are 1.493% and 5.2236% respectively,indicating that the proposed expression of mixing rule is reasonable.This may provide a fundamental method for studying and predicting the properties of supercritical fluids.     

Determination of petroleum sulfonates in crude oil by column-switching anion-exchange chromatography

A column-switching anion-exchange chromatography method was described for the separation and determination of petroleum monosulfonates （PMS） and petroleum disulfonates （PDS） in crude oil that was simply diluted with the dichloromethane/methanol （60/40）. The high performance liquid chromatography （HPLC） system consisted of a clean-up column and an analytical column, which were connected with two six-port switching valves. Detection of petroleum sulfonates was available and repeatable. This method has been successfully applied to determine PMS and PDS in crude oil samples from Shengli oil field.     

A Concise and Convenient Synthesis of Stilbenes via Benzils and Arylmethyldiphenylphosphine Oxides

A new and convenient synthetic method has been developed for the construction of stilbenes bearing electron-withdrawing group（s） by using benzils and arylmethyldiphenylphosphine oxides via sequences involving Wittig-Horner reaction and a rearrangement in the presence of t-BuOK in toluene under mild conditions. This approach could be readily applied to a facile synthesis of biologically important natural products, resveratrol and its derivatives, such as trimethoxystilbenes 1 （Z） and 2 （E）.     

A New Kinetic Method of Processing TA Data

A new method of investigating the kinetic parameters and mechanism functions of a solid phase reaction is presented. This method is to analyze the data based on the use of these data at the same temperature and the same degree of conversion on a series of TA curves with different heating rates, so that the kinetic triplet--the activation energy E, the pre-exponential factor A and the analytical form of the function of conversionf(α) can be obtained. The main advantage of this method is that the values of E and f(α) are obtained respectively, and the determination of f(α) is not under the influence of the value of E and the calculation of the value of E is not influenced by thef(α) either.     

LaZnxFe1-xO3 钙钛矿型纳米催化剂的制备、表征及其甲苯燃烧性能

 Nanostructured LaFeO3 and substituted LaZnxFe1-xO3 (x = 0.01, 0.05, 0.1, 0.2, and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of toluene. Their structures and surface properties were investigated by X-ray diffraction, Fourier transmission infrared spectroscopy, BET surface area, and scanning electron microscopy. Characterization data revealed that the total insertion of zinc into LaFeO3 takes place when x ≤ 0.1. However, ZnO segregation occurs to some extent, especially at x > 0.1. The performance of these perovskites was evaluated by toluene combustion. The catalytic activity of the catalysts increased substantially with an increase in zinc substitution. These results can be attributed to the cooperative effect between LaZnxFe1-xO3 and the zinc oxide phases. The relative concentration of these phases determines their oxygen activation ability and reactivity.     

Effect of Preparation Methods of Bi2O3 Nanoparticles on their Photocatalytic Activity

Bi2O3 nanoparticles were prepared by means of ammonia precipitation, polyol mediated methods and microemulsion chemical method. The structure and properties of the as-prepared nanoparticles, having been submitted to a heat-treatment test at 750℃, were characterized by means of XRD. BET, XPS and UV-Vis absorption techniques. The photocatalytic oxidation reactions of benzene, toluene and xylene were used as the model reaction to measure the photocatalytic activity of Bi2O3 nanoparticles, respectively. The results show that the crystallite size of Bi2O3 prepared with different methods and calcined at 750℃ were 50. 6, 38.5 and 31.5 nm, respectively. The photocatalytic activity of Bi2O3 nanoparticles prepared with the microemulsion chemical method was higher than that of the particles prepared with the polyol mediated method; and that of the particles prepared with the micromulsion chemical method was the highest among the three. The degradation rates of the three pollutants xylene, toluene and benzene decreased in sequence.     

ANALYSIS OF PETROLEUM ACIDS IN DUSHANZI DISTILLATE

A method which involves conversion of carboxylic acids to corresponding hydrocarbons and determination of high-resoiution mass spectrometry has been applied to the analysis of petroleum acids in Dushanzi distillate and resulted in compound class identification of petroleum acids which have not been reported previously in Xinjiang petroleum.     

Investigations of Retention Rule in Reversed-Phase High Performance Liquid Chromatography——Theoretical Consideration of Retention Convergence and Experimental Verification

This paper studied the effect of different chromatographic parameters in RP-HPLC (for example,composition of mobile phase, temperature, number of carbon atoms within the solute molecules, solvent molecules and alkyl ligand on bonded phase surface) on the retention convergence based on the displacement adsorption multi-interaction model,and derived a few retention convergent equations by using thermodynamic method,which have been verified by a great deal of experimental data of homologous series.Moreover,we have developed a general method, which can calculate the coordinate values of various retention convergent points by computer directly from experimental data,and the results predicted are in good agreement with that obtained by using plotting method.     

Adsorption desulfurization of model gasoline by metal–organic framework Ni_3(BTC)_2

This work presented the synthesis of Ni-based metal-organic framework material with a paddle-wheel structure Ni_3(BTC)_2(Ni-BTC) and its application in thiophene(TP) adsorption from gasoline distillate by batch method. Adsorption isotherms of TP, cyclohexene, and toluene in cyclohexane onto Ni-BTC were conducted at 298–308 K to interpret the different effect of cyclohexene and toluene on TP adsorption.The results showed that, compared with cyclohexene, toluene addition in model gasoline led to a more evident decline in sulfur capacity of Ni-BTC, which is opposite to isostructural HKUST-1. The adsorption isotherms of TP, cyclohexene and toluene fit Langmuir model, S-type model and Temkin model well, respectively, indicating that the adsorption mechanisms of TP and the two competitors are different from one another. The adsorption capacities on Ni-BTC followed the order of cyclohexene toluene TP at the same equilibrium concentrations, implying the order of the adsorption affinities, which is in good agreement with the different extent of influence by the two competitors. The enthalpy of TP adsorption on Ni-BTC was estimated to be-80.01 kJ/mol, almost twice that on HKUST-1. The poor reusability of Ni-BTC in batch experiment, which is owing to its sensitivity to the air, can be prevented from regenerating used Ni-BTC in fixed-bed reactor by N_2 flow. The difference between Ni-BTC and HKUST-1 in maximum adsorption capacity(q_0), H of TP adsorption, and stability demonstrates that the central metal in isostructural MOFs plays a key role in adjusting the desulfurization performance, which may open up a potential avenue for the development of MOF-based adsorbents with superior desulfurization performance.     

Application of multivariate techniques for optimization of direct method for determination of lead in naphtha and petroleum condensate by electrothermal atomic absorption spectrometry

A direct method is proposed for the determination of lead in naphtha and petroleum condensate by electrothermal atomic absorption spectrometry (ET AAS) using palladium as a permanent modifier. The procedure includes the dilution of 3 mL of sample (naphtha or petroleum condensate) to a final volume of 10 mL with xylene, and direct injection of 30 μL of this solution into the graphite furnace. The optimization of the instrumental conditions was performed using multivariate techniques. Firstly, a 2³ full factorial design was performed for preliminary evaluation of the factors: pyrolysis time, pyrolysis temperature and atomization temperature. This experiment showed that in the studied levels only the factors pyrolysis time and atomization temperature were significant. Then, a 3² full factorial design was performed for the determination of the critical conditions of these variables. The method allows the determination of lead using the standard calibration technique with a calibration curve from 2.6 to 30 μg L⁻¹ (correlation coefficient higher than 0.998). A limit of detection (3σ) of 0.8 μg L⁻¹ and a characteristic mass of 35 pg were obtained in the presence of palladium as modifier. The precision expressed as relative standard deviation (RSD) was 1.5 and 0.8% for lead concentrations of 3.0 and 30 μg L⁻¹ (n = 10). Recovery studies demonstrate that lead can be determined in naphtha and petroleum condensate using calibration with organic standard solutions. This method was applied for the determination of lead in three petroleum condensate and two naphtha samples. The concentrations found for the petroleum condensate was between 2.7 and 5.7 μg L⁻¹, while the naphtha samples did not contain any detectable lead.     

Development and optimization of an HPLC–DAD method for quantification of six petroleum hydrocarbon compounds in aqueous samples

Benzene, toluene, and xylene isomers (BTXs) and pyrene, benzo(b)fluoranthene, and benzo(a)pyrene (polycyclic aromatic hydrocarbons) are common pollutants found in many industrial effluents and in aquifers due to fossil fuels spill from underground storage reservoirs. For these reasons, the determination of these compounds has gained importance in the last decades. In this work, a simultaneous, fast, and accurate quantification of six petroleum hydrocarbon compounds (such as BTXs, pyrene, benzo(b)fluoranthene, and benzo(a)pyrene) using a high-performance liquid chromatography–diode array detector method has been demonstrated. The proposed method is suitable for the direct aqueous sample evaluation and also brings advantages, including the use of small volumes of organic solvents, with high resolution, reducing the analysis cost. The method was also checked using synthetic and real samples, including those containing surfactants, commercial gasoline, and river water samples spiked with petroleum hydrocarbon compounds.     

2-氨基-4-氯-5-甲基苯磺酸的合成研究

2 氨基 4 氯 5 甲基苯磺酸是合成染料和颜料的重要中间体 ,主要用于合成Ｃ .Ｉ.颜料红等[1] 。目前该产品的合成是以对硝基甲苯为原料 ,经氯化、还原、磺化而成[2 ] 。磺化过程需在压力容器中进行 ,存在成本高 ,溶剂及副产物二氯苯、多氯联苯有毒等问题[3,4] 。为此采用无毒、价廉的汽油和石油醚作为混合溶剂 ,常压下合成 2 氨基 4 氯 5 甲基苯磺酸是本工作的目的。1　实验部分1 .1　主要仪器和药品Ｘ4熔点测定仪 ,日本 2 6 0 5 0型红外光谱仪 ,日本ＬＣ 6Ａ高效液相色谱仪 ,ＪＥＯＬＦＸ 90Ｑ型核磁共振光谱仪 ,美国ＰＥ 2 4 0 0自动元…     

Absorption of toluene in poly(aryl-ether-ether-ketone)

The absorption and swelling of poly(aryl-ether-ether-ketone) (PEEK) in toluene as a function of resin morphology and temperature in the range 35–95°C was investigated. In all cases the weight gain curves exhibit three characteristics: (1) an induction period, which is a strong function of both temperature and initial crystallinity, (2) a main absorption region, which is linear with square-root time, and (3) a final equilibrium value, namely, solubility. The solubility of amorphous PEEK decreases with temperature and the heat of solution is ?0.93 kcal/mol. The induction period varies with the fourth power of the crystallinity and decreases with temperature with an apparent activation energy of 50 kcal/mol. The strength of the interaction between the crystalline regions is markedly reduced at temperatures greater than 80°C. Swelling accompanying the absorption of the toluene is highly anisotropic with most of the dimensional changes occurring in the thickness direction. The deswelling process, however, is essentially isotropic. The concentration of toluene in solution has a strong effect on the transport process; the equilibrium solubility of toluene in amorphous PEEK immersed in a toluene/iso-octane mixture is a linear function of toluene concentration; but the pseudo-diffusion coefficient for the absorption of toluene varies approximately with the fourth power of its concentration.     

光点击化学修饰石油树脂研究

为改善传统石油树脂改性方法能耗高、效率低等缺陷,本文应用点击化学,在常温下,以甲苯为溶剂,以Darocur1173为光引发剂,在UV-LED灯辐照下,通过3-巯基丙酸与DCPD石油树脂发生巯基-烯加成反应,制备的产物命名为DCPD-COOH。以三苯基膦为催化剂,用甲基丙烯酸缩水甘油酯(GMA)与DCPD-COOH反应,制备了可光固化的丙烯酸酯石油树脂,命名为DCPD-A。固化漆膜的设计配方:DCPD-A(50份)、活性稀释剂甲基丙烯酸羟乙酯(HEMA,50份),光引发剂Darocur1173(5份)。在该配方下制得的固化漆膜其附着力达到0级,铅笔硬度为2H。制备的DCPD-A与极性溶剂或者极性树脂的相容性较好,可应用于光固化涂料和光固化油墨等领域。     

气相色谱法测定甘宝素中的甲苯残留量

采用毛细管气相色谱法快速测定甘宝素产品中的甲苯残留量。样品经甲醇稀释,氢火焰离子化检测器检测,外标法计算含量。甲苯的质量浓度在3.2~25.6 mg/L范围内与色谱峰面积线性良好,相关系数r=0.999 3,方法的检出限为1.16 mg/L,样品的加标回收率为96.5%~102.8%(n=6),测定结果的相对标准偏差为3.2%~4.5%。该方法操作简便,灵敏度高,适合于实际生产中甲苯残留量的快速测定。     

Study on the “induction period” of toluene ethylation performed on HZSM-5 zeolite catalysts

Formation and consumption of activated toluene species results in an “induction period” in the toluene ethylation on HZSM-5 zeolite, and toluene pretreatment can enhance the activity of HZSM-5 in the reaction by producing activated toluene species.     

甲苯磺酸异构体的气相色谱分析

为克服在甲苯磺酸异构体定量分析结果中重复性和准确性差的问题，从多种色谱固定液中选出合适固定液，以正十十一烷作为内标物，优化了色谱条件，对气相色谱法研究甲苯磺酸乙酯异构体中的诸多影响因素进行了比较，确定了汽化室温度对于邻、间、对甲苯磺酸乙酯异构体准确测定的影响作用。     

Determination of isothermic compressibility of solvent from changes in the absorbance of a dye solution under pressure

A new method of determination of the isothermic compressibility coefficient of a solvent from a change in the absorbance of a solution of the dye under elevated pressure (up to 100 MPa) was proposed. The method was checked by comparison with the known data for carbon tetrachloride and toluene at 25 °C. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2049–2052, December, 2006.     

改进的Gattermann-Koch反应

Gattermann-Koch 反应是实验室制备对-甲基苯甲醛(p-TAL)的常用方法。通常认为,氯化亚铜在反应体系中是一种必要的助剂,否则,常压下甲苯羰基化就无法进行。1979年,голубев曾不用氯化亚铜和氯化氢为助剂进行 Gattermann-Koch 反应。一年后,Toniolo 报道了以三氯化铝为催化剂,氯化亚铜-三苯基膦络合物为助剂的芳香烃羰基