稀土中变催化剂的研究

一、前言一氧化碳与水蒸气在催化剂存在下生成氢气的变换反应,已被广泛应用在工业生产上。如:合成氨工业、合成甲醇及合成汽油水煤气中H_2/CO调整、城市煤气CO含量的控制、煤炭综合利用中的液化、石油加工中重油和页岩油的加氢处理等,都可依靠此     

茂金属催化剂开发及应用

本文介绍了茂金属催化剂的开发以及利用茂金属合成的聚乙烯、聚丙烯、聚苯乙烯、ＥＰＤＭ等聚合物方面的进展。     

工业催化剂的研制与开发——我的实践与探索

本刊自本期开始,开辟《专家论坛》栏目,约请各方知名专家撰写其专长方面的论文、专著,供广大读者学习、钻研与探讨。1997年第7期本刊曾介绍本刊顾问两院院士闵恩泽教授的专著《工业催化剂的研制与开发 我的实践与探索》中国石化出版社出版,该书是著者积四十年从事工业催化剂研制与开发的丰富经验,撰写而成,是国内第一部较全面、系统地论述工业催化剂的研制开发经验、体会和方法的专著。因此,经本刊编辑部与中国石化出版社联系并征得著者同意,自本期开始在《专家论坛》栏目连续摘要转载该书主要章节,以飨广大读者。     

工业催化剂的研制与开发

第八章 新催化材料 第五节 我们的又一实践——非晶态合金新催化材料的研究 非晶态合金是60年代开发的一种新型金属材料,对其机械、电磁、防腐等性能已进行了大量研究,并已在磁性材料、防腐材料等方面获得工业应用。关于它用作催化材料的研究,始于80年代初。 目前制备非晶态合金的方法主要有骤冷法和化学法。骤冷法制备非晶态合金的基本原理是:将熔融的合金压置到高速旋转的铜辊上使其骤冷,其冷却速     

中国石化催化剂出口总量超万吨

截至2007年12月中旬,中国石化催化剂分公司2007年出口各类催化剂产品首次突破10kt,发货达12773．87t,销售收入达到2．6亿元。出口产品除了原有的FCC催化剂、DCC催化剂、加氢催化剂、聚乙烯催化剂和聚丙烯催化剂继续保持良好势头外,又增加了连续重整催化剂、甲苯歧化催化剂、吸附剂和多种分子筛新品种,第一次出现了所属各分（子）公司全部实现出口创汇的局面,     

ON THE PREDICTION OF HEATS OF VAPORIZATION OF PURE COMPOUNDS

An expression to predict the values of the latent heat of vaporization of pure compounds at their normal boiling point has been developed. A knowledge of the critical temperature, critical pressure, normal boiling point and acentric factor of the compound coupled with the use of generalized correlations for second virial coefficient and liquid molar volume allows to obtain good estimates, particularly for alcohols and ketones. Results for 71 various substances are compared with experimental values and with the results of eight other equations available in the literature. The possibility of using the calculated heats of vaporization at the normal boiling point to estimate values at other temperatures is discussed.     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

ON THE PREDICTION OF HEATS OF VAPORIZATION OF PURE COMPOUNDS

An expression to predict the values of the latent heat of vaporization of pure compounds at their normal boiling point has been developed. A knowledge of the critical temperature, critical pressure, normal boiling point and acentric factor of the compound coupled with the use of generalized correlations for second virial coefficient and liquid molar volume allows to obtain good estimates, particularly for alcohols and ketones. Results for 71 various substances are compared with experimental values and with the results of eight other equations available in the literature. The possibility of using the calculated heats of vaporization at the normal boiling point to estimate values at other temperatures is discussed.     

COMPARISON OF A PAIR OF THREE PARAMETER EQUATIONS OF STATE

The lattice fluid (LF) equation of state derived by Sanchez and Lacombe from a lattice model is compared to the empirical Peng-Robinson (PR) equation for normal alkane fluids ranging from methane to heptadecane in molecular weight. With respect to vapor pressure predictions, the equations are both good. The LF equation is superior, especially for higher molecular weight fluids, to the Peng-Robinson equation in predicting saturated liquid densities. For carbon numbers less than 6, the PR equation predicts heats of vaporization more accurately, whereas for carbon numbers greater than 9 the LF equation is more accurate than the PR one for temperatures lower than about 95% of critical.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

CHANGES OF PROPERTIES OF GLASS RESULTING FROM CHANGES OF COMPOSITION *

Equations are given for the calculation of changes of density, refractive index, and other optical constants produced by the addition of a known relative weight of a given component to a base glass. Corresponding equations for the substitution of one component for another are also given. Values are computed and listed for the initial fractional rate of change of refractive index (n_D) when various components are added to (a) pure SiO₂ and (b) a sodium silicate glass containing 50% of Na₂O by weight.     

ON THE PREDICTION OF POROSITY OF BEDS COMPOSED OF MIXTURES OF SPHERICAL PARTICLES†

A semi-theoretical study of porosity of particulate beds composed of mixtures of various size spherical particles has been performed. A model for mixtures of only two particle sizes is developed and is used to identify several dimensionless parameters which are correlated by comparing predictions with the data. The model is then extended to evaluate porosity of mixtures of a large number of particle sizes and distributions. The predictions from the model are found to compare quite well with the data taken in this work and the existing data in the literature when unavailability of a certain fraction of pores formed of largest size particles in the mixture is accounted for.     

COMPARISON OF A PAIR OF THREE PARAMETER EQUATIONS OF STATE

The lattice fluid (LF) equation of state derived by Sanchez and Lacombe from a lattice model is compared to the empirical Peng-Robinson (PR) equation for normal alkane fluids ranging from methane to heptadecane in molecular weight. With respect to vapor pressure predictions, the equations are both good. The LF equation is superior, especially for higher molecular weight fluids, to the Peng-Robinson equation in predicting saturated liquid densities. For carbon numbers less than 6, the PR equation predicts heats of vaporization more accurately, whereas for carbon numbers greater than 9 the LF equation is more accurate than the PR one for temperatures lower than about 95% of critical.