Catalytic Cracking of Naphtha to Light Olefins

A catalytic process that produces light olefins from naphtha was developed to improve the yield of the conventional steam cracker. In laboratory-scale tests, a newly developed zeolite-based catalyst at a reaction temperature of 650°C produced an ethylene-plus-propylene yield of about 60%, which is about 10% higher than the conventional process operated at around 820°C. A feasibility study carried out for a catalytic cracking process using the developed catalyst, that cracks 3000 tons-naphtha/day, indicated an energy saving of about 20% compared with the conventional process.     

Distribution of Elements among Fractions of Petroleum Tars and Bitumens from West Siberian Industrial Oil

Distribution of C, H, N, S, and O among polar and nonpolar components of malthenes and asphaltenes of initial tars and quality and substandard bitumens obtained from them is studied by chemical and elemental analyses and ¹H and ¹³C NMR.     

汽油中气体组分含量的快速分析

采用美国HP6890炼厂气分析多维填充柱色谱仪,建立了汽油中气体组分含量快速分析方法。采用汽油直接进样,校正归一化法定量,测定汽油中CO2、H2S和各气体烃组分的含量,完成一个样品的分析仅需22min。实验表明,该方法有很好的精密度,各气体组分浓度值的相对标准偏差均小于4．5％。     

Liquid-Vapor Phase Equilibria in Binary and Ternary Subsystems Constituted by Pyrocondensate Components from the Pyrolysis of Straight-Run Naphtha

Liquid-vapor equilibrium in the binary subsystems of the ethylbenzene-o-xylene-α-methylstyrene-p-vinyltoluene-dicyclopentadiene-indene system was predicted using UNIFAC group model and studied experimentally. To assess the reliability of parameters, the liquid-vapor equilibrium was studied experimentally in the ternary systems and compared with the calculated data.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 403–407.Original Russian Text Copyright © 2005 by Prikhod’ko, Komarova, Gorelova, Gorlova, Bondaletov.     

Divinyl Sulfoxide: XI. Selective Addition of Carbonodithioate Anions to Divinyl Sulfoxide in the Water-Benzene System

Selective monoaddition of carbonodithioate anions to divinyl sulfoxide gives rise to O-alkyl S-[2-(vinylsulfinyl)ethyl] carbonodithioates [ROC(S)SK, R = Et, Bu; 42–50°C, 6 h, NaHCO₃, aqueous benzene].     

气相色谱—裂解炉联用分析硅氨烷高温裂解逸出气体

以气相色谱与高温裂解炉联用，对用于制备Ｓｉ－Ｃ－Ｎ微粉的前体「ＳｉＣｘＮｙＨｚ」ｎ在Ａｒ气条件下高温裂解过程中所逸出的ＣＨ４、Ｈ２气体进行了分析。     

The Pyrolysis of Azides in the Gas Phase

The chemistry of the non-metallic elements has in recent years passed through a period of rapid development, often referred to as its “renaissance”. To emphasize just one of the key facets: numerous short-lived molecules containing multiple bonds to elements of the third and higher periods have been discovered, often accompanied by the planned synthesis of derivatives which are sterically shielded by bulky groups and thus kinetically stabilized. Thus today molecules such as silabenzenes H₆C_6?nSi_n and silaethenes H₂Si?CH₂ or R₂Si?CR₂, disilenes R₂Si?SiR₂ and diphosphenes RP?PR, silaphenylisonitrile H₅C₆? N?Si, or methylidyne-phosphanes R? C?P, are all well-known species. Sandwich compounds with P₆ rings or silicon centers demonstrate that there are now hardly any barriers to impede the imagination of the non-metal chemist. In sharp contrast is our lack of knowledge regarding the “microscopic” pathways of chemical reactions: thus apart from information provided for example by molecular beam experiments, or from exact numerical calculations involving species consisting of only a few atoms, it remains largely unknown from which directions medium-sized molecules must approach each other to successfully collide and form a “reaction complex”, in which way their structures are changed in such a process or which role is played by molecular dynamics in the energy transfer.–The pyrolysis of azides X? N₃, i.e. compounds which tend to explode violently when ignited in the condensed phase but can be heated in low-pressure gas flow systems without much risk, illustrates that studies of reactive intermediates are of interest not only because novel molecules may be discovered and isolated, and thereby possibilities for synthesis expanded. Moreover, some aspects of the “microscopic” pathways of these azide pyrolyses can be described satisfactorily on the basis of calculated energy hypersurfaces, and the influence of molecular dynamics becomes experimentally visible in the “chemical activation” of intermediates which leads to their “thermal explosion”.     

Continued Fractions and Upper and Lower Bounds in the Brillouin-Wigner Perturbation Scheme

A derivation of approximants to a continued fraction development of the energy is presented. It is based on the techniques of infinite order perturbation theory and inner projection of operators. The approximants have been introduced before; here their formal nature is clarified and conditions under which they exhibit extremal properties are presented. The oscillatory behaviour about the true eigenvalue, observed previously in the Mathieu problem, is explained. Une dérivation des approximations successives pour un développement en fraction continue de l'énergie est presentée. Elle est fondée sur les méthodes de la théorie des perturbations d'ordre infini. Ces approximations sont déjà connues; ici leur nature formelle est clarifiée et des conditions pour qu'ils aient des propietées extrémales sont données. Le comportement oscillatoire autour de la valeur propre exacte, observé auparavant, est expliqué. Es wurde eine Ableitung von Annäherungen einer Entwicklung der Energie in Kettenbrüchen beschrieben. Sie ist auf Methoden der Störungstheorie unendlicher Ordnung gegründet. Diese Annäherungen sind schon früher eingeführt worden; hier wurde ihre formale Natur abgeklärt und Bedingungen, unter welchen sie Extremaleigenschaften besitzen, wurden hergeleitet. Die Schwingungem um den exakten Eigenwert, die früher in dem Mathieuproblem beobachtet worden sind, wurder hier erklärt.     

同时裂解甲基化气相色谱法在油漆种类鉴别中的应用

在刑事侦察技术领域,对油漆等微量物证的快速、微量分析非常重要。油漆中的成分通常含有羧基、羟基、氨基等极性基团,用裂解气相色谱法（Py—GC）分析,其裂解产物的色谱峰数较少,特征性较差。同时裂解甲基化气相色谱法（SPM-GC）可用于分析鉴别含有羧基、羟基、氨基等强极性基团的大分子或聚合物。在以前的研究中,已经将SPM-GC应用于油脂和胶粘剂等物质的鉴别分析,取得了较好的结果。本实验主要用SPM—GC对微量物证分析中常遇到的部分品牌油漆进行了鉴别分析。     

裂解气相色谱法分析铸造用聚苯乙烯泡沫塑料热解产物

采用裂解气相色谱法研究了汽化模铸造工艺用聚苯乙烯泡沫塑料在４５０～１０００℃温度范围内热分解产物的分布,定量测定了４种主要蒸气态热分解产物的含量。结果表明,所采用的分析方法对研究铸造用高分子材料热分解产物行之有效,而且方法简单、快速、准确。     

Kinetics of Isothermal Pyrolysis of Iodomethanes in the Gas Phase

The limiting step of the isothermal pyrolysis of gaseous iodomethane (CH₃I → 3/4CH₄ + 1/2I₂ + 1/(4n)C _n ) and diiodomethane (CH₂I₂ → 1/2CH₄ + I₂ + 1/(2n)C _n ) are the reactions 2CHI → C₂ + 2HI and 2CI₂ → C₂ + 2I₂, respectively. The rate constants of these reactions were determined.     

气相色谱/质谱测定汽油中的元素硫

在气相色谱/质谱(GC/MS)联用仪上,研究了汽油中元素硫存在的结构,并采用外标法定量,开发出了汽油中元素硫测定的新方法。样品直接进样(进样量1 μL),完成一个样品分析只需16 min,最小检测量(MDQ)为9.55 pg。与现有的其他元素硫分析方法相比,该方法更简便 快速 灵敏,且无干扰。该方法选择了最佳分析条件,因而线性范围宽(0.01-100 mg/L),线性相关系数大于0.9995;方法精确度高,元素硫检测的相对标准偏差(RSD)＜5%,回收率为93.01%-106.21%。该方法样品用量少     

Direct and Highly Selective Conversion of Synthesis Gas into Lower Olefins: Design of a Bifunctional Catalyst Combining Methanol Synthesis and Carbon–Carbon Coupling

The direct synthesis of lower (C₂ to C₄) olefins, key building‐block chemicals, from syngas (H₂ /CO), which can be derived from various nonpetroleum carbon resources, is highly attractive, but the selectivity for lower olefins is low because of the limitation of the Anderson–Schulz–Flory distribution. We report that the coupling of methanol‐synthesis and methanol‐to‐olefins reactions with a bifunctional catalyst can realize the direct conversion of syngas to lower olefins with exceptionally high selectivity. We demonstrate that the choice of two active components and the integration manner of the components are crucial to lower olefin selectivity. The combination of a Zr–Zn binary oxide, which alone shows higher selectivity for methanol and dimethyl ether even at 673 K, and SAPO‐34 with decreased acidity offers around 70 % selectivity for C₂–C₄ olefins at about 10 % CO conversion. The micro‐ to nanoscale proximity of the components favors the lower olefin selectivity.     

Phosphine-Catalyzed Reactions of Imides and Hydrophosphoryl Compounds Addition to Divinyl Sulfone

Russian Journal of General Chemistry - An efficient method for the phosphine-catalyzed bisaddition of P(O)H compounds and cyclic imides to divinyl sulfone has been developed. The reaction proceeds...     

裂解气相色谱/质谱法检验复印墨粉

复印墨粉检验分析在经济案件侦查以及墨粉配方研究方面具有十分重要的意义。采用裂解气相色谱技术,对收集到的复印墨粉进行分离分析,并用裂解气相色谱/质谱联用技术,对所得裂解峰进行归属。分析结果的重复性与稳定性良好,复印件上墨粉与原墨粉分析结果一致。对不同厂家与牌号的墨粉进行区分与归类,为墨粉鉴别提供了依据。     

C_5馏分及其羰化产物的毛细管气相色谱分析

石油裂解副产物C5馏分及其羰化产物是成分较为复杂的混合物,尤其是C5馏分中1,3-环戊二烯和顺-1,3-戊二烯的物性更为接近。用SE－54弹性石英毛细管柱和角鲨烷玻璃毛细管柱分别对C5馏分及其羰化产物进行了分析,使各组分达到了很好的分离。     

毛细管气相色谱法测定烷烯分离装置产物中烯烃及烷烃

Olefin and paraffin contents in products of Olex unit were determined by capillary gas chromatography,instead of mass spectrometry,as a routine assay method.The reproducibility of quantitation has also been evaluated and the results are satisfactory.