碳热还原二氧化硫制备硫黄的研究进展

碳热还原二氧化硫制备硫黄是一种绿色资源化的SO₂治理技术。本文对碳热还原二氧化硫制备硫黄的研究进展进行了综述, 介绍了国内外关于碳与二氧化硫反应机理及反应动力学的研究, 讨论了C/SO₂摩尔比、反应温度、反应时间、反应气氛、碳的类型以及矿物质等因素对碳热还原二氧化硫反应的影响规律。得出了反应实现较高SO₂转化率和S产率所需要的条件。并指出微波辐照条件下, 碳还原二氧化硫的反应优势明显, 研究其反应机理和产物生成规律对于该技术的应用意义重大, 是未来发展的重要方向。     

[60]富勒烯三元环化反应及其衍生物功能研究

对[60]富勒烯的三元环化反应及其衍生物的功能研究进行了概述,讨论了[60]富勒烯的三元环化反应的发生机理.重点阐述了[60]富勒烯三元环化典型反应及获得的富勒烯衍生物的生物医药功能等,对今后的工作进行了展望.     

Kinetics of the Low-Temperature Selective Catalytic Reduction of NO with NH3 Over Activated Carbon Fiber Composite-Supported Iron Oxides

A kinetic analysis in a variety of conditions (gas composition and temperature) has been conducted on catalysts of iron oxides supported on activated carbon fiber composites (ACFC). Additionally, experiments of temperature-programmed desorption (TPD) of NO were conducted on the catalysts in order to reveal mechanistic features of the low-temperature SCR reaction. In the light of current SCR literature and previous work, a qualitative picture of the catalytic behavior of low-temperature SCR catalysts is offered. Apparently, the strength of adsorption of NO during the low-temperature SCR reaction is responsible for the governing reaction mechanism. Thus, highly stable nitrates formed on the surface provoke catalyst deactivation and reaction through an ER mechanism, with NO reacting from the gas phase, whereas the absence of these nitrates permits reaction of less stable nitrites from the catalyst surface, following an LH-type mechanism. This is the case for the ACFC-supported iron oxide catalyst analyzed in this work.     

焦袂糠酸新工艺合成的研究

焦袂糖酸是合成麦芽酚系列产品的重要中间体，本文以糠醇为原料，用氯气氧化法制备了焦袂糠酸，研究了有机碱的存在，无机盐的存在，反应温度，反应时间，反应介质类型及反应介质，pH值等因素对反应的影响，以产率为目标，用正交实验法提出了最佳工艺条件。     

Economic feasibility of silica and palladium composite membranes for industrial dehydrogenation reactions

This article addresses the economic feasibility of silica and palladium composite membranes for gaseous dehydrogenation reaction schemes. Unlike other methodologies addressed so far, this work presents the economic assessment of dehydrogenation reaction schemes using a conceptual design based simulation methodology for the comparative economic assessment of membrane reactors with conventional reactors. The suggested methodology is applied to two industrially prominent reaction schemes namely styrene (from ethylbenzene) and propylene (from propane) production using silica and palladium composite membrane reactors. Various sub-cases studied in this work include the influence of membrane area per reaction zone volume, reaction zone temperature, reaction and permeation zone pressure, membrane thickness and sweep gas flow rate on process economics. Based on this work, the propylene production scheme is evaluated to provide 60–70% excess profits using membrane reactors when compared with the conventional reactor based technology. However, the gross profit profiles for both conventional reactor and membrane reactor configurations have been found to be similar for styrene production case. For all cases, the cost contribution of membranes and other auxiliary equipment is estimated not to exceed 20% of the total costs. In addition, similar economic performance has been observed for both silica and palladium membranes. Based on these studies, it has been concluded that the industrial applicability of membrane reactors is economically suitable for those dehydrogenation reactions that enable significant conversion enhancement with respect to the conventional reactor technologies.     

Studies on cyanoethylation of jute fiber

Changes of reaction variables upon the reaction of jute fiber with acrylonitrile, like concentration of sodium hydroxide, reaction time, and reaction temperature, were studied in the present work. Benzene and dioxane were used as diluents for acrylonitrile and reactions were conducted in their presence in different amounts. Jute fibers were delignified progressively and their effect on the cyanoethylation reaction was studied. It was found that fiber swelled with ethylene diamine, prior to cyanoethylation, gave a higher yield of cyanoethylated jute. Some preliminary work was done to investigate the distribution of reacted chemicals among its major constituents. An FTIR study was performed to show the partial substitution of hydroxyl groups by the cyanoethyl group. The FTIR study also revealed that not only did hydroxyl groups of the cellulosic component of jute react with acrylonitrile but hydroxyl groups of lignin also took part in the reaction. © 1996 John Wiley & Sons, Inc.     

邻苯二酚与甲代烯丙基氯的醚化反应动力学

呋喃酚（2,3-二氢-2,2-二甲基-7-苯并呋喃酚）是制造杀虫剂呋喃丹（克百威）的重要中间体．呋喃酚的工业生产主要有邻硝基酚法、环已酮法和邻苯二酚法．同其他生产工艺比较,邻苯二酚法具有生产简单、收率高等优点．因此,目前工业上主要采用邻苯二酚法．     

六氟丙烯二聚体及其衍生物

介绍了六氟丙烯二聚体的结构、制造方法，及其各种化学反应和衍生物。并叙述了上述各种反应的催化剂体系和机理分析。     

Stand reaction of linseed oil

Several theories have been proposed concerning the stand oil reaction but no precise reaction scheme has been described. In this work, the stand reaction of linseed oil was characterized in order to determine the nature of the products formed during this reaction. Using complementary analytical techniques (more especially NMR and mass spectrometry), the existence of two different reactions was demonstrated: the Diels–Alder addition between fatty acid chains and the addition of a methylene radical on double bonds, followed by combination or elimination reactions.     

The effect of pre-curing UV-irradiation on the crosslinking of silicone rubber

A recent work made use of selective pre-curing UV-irradiation and its effect on the kinetics of reaction of heat-cure silicone elastomers to spatially tune its viscoelastic properties and design architected solid membranes. The present study adds to the possibility of controlling the local properties of spatially graded materials by exploring the effect of key processing parameters such as the UV dose and the silicone mix thickness on the vulcanization kinetics. Dynamic Differential Scanning Calorimetry measurements have been performed showing that, over the conditions explored, the higher the UV dose, the slower the kinetics reaction. Additionally, complete crosslinking was always reached. Companion modeling effort using the Kissinger reaction model is attempted and the effects of processing parameters on the apparent activation energy are discussed. This work is a crucial first step towards the control of the processing settings needed to design architected silicone rubber membranes with spatially controlled mechanical property gradients obtained from a unique macromolecular network.     

Investigation of the kinetics for the photosynthesis of methylchloroform

In this work the photochemical chlorination of 1,1-dichloroethane to 1,1,1-trichloroethane in the gas-phase is investigated. It can be shown, that in the analysis of this reaction system exponential equations for the reaction rates are in practice superior to equations based on mechanistical considerations. The use of lower reactant concentrations leads to higher selectivities for this reaction; quantum yields of 10⁴ and more permit the use of weak lamps.     

Estimation of time-dependent reaction coefficient with extended Kalman filter approach

This work introduces an extended Kalman filter (EKF) to the estimation of the unknown time-dependent reaction coefficient based on the concentration measurement data. An autocatalytic reaction pathway is chosen as a model problem. This inverse estimation algorithm does not assume any functional form of the reaction coefficient. The performance of the proposed algorithm is verified through the numerical experiments with the exact and the contaminated concentration measurement data.     

Kinetic modeling of non-hydrocarbon/nitric oxide interactions in a flow reactor above 1,400K

The reduction of nitric oxide by reaction with non-hydrocarbon fuels under reducing conditions at comparatively higher temperature has been studied with a detailed chemical kinetic model. The reaction mechanism consists of 337 elementary reactions between 65 chemical species based on the newest rate coefficients. The experimental data were adopted from previous work. Analyses by comparing existing experimental data with the modeling predictions of this kinetic mechanism indicate that, at comparatively high temperature, apart from the reaction path NO→HNO→NH→N₂, NO+N→N₂ is also prominent. In the presence of CO, NO is partly converted to N by reaction with CO. Based on present model, the reduction of NO at high temperature, which was usually underestimated by previous work, can be improved to some extent. This work was presented at the 7 ^th China-Korea Workshop on Clean Energy Technology held at Taiyuan, Shanxi, China, June 26–28, 2008.     

Crosslinking and scission in radical-promoted functionalization of polyethylene

We reported earlier on grafting hexafluoroisopropanol groups onto polyethylene through the reaction of polyethylene with hexafluoroacetone and di-t-butyl peroxide. The modified polyethylene was partially crosslinked. In this work, we adapted the Charlesby–Pinner Equation to estimate the ratio of chain scission to crosslinking in the reaction.     

N-异丙基羟胺除氧反应动力学

研究了N-异丙基羟胺(IPHA)与去离子水中游离氧反应的动力学. 以15% NaOH水溶液为pH调节剂,通过考察不同pH值、反应温度和IPHA用量下水中游离氧浓度随时间的变化规律,建立了IPHA除氧反应动力学模型,经过数据分析及反应机理研究对所建动力学模型进行简化,推导出IPHA与游离氧反应的动力学方程,该反应为假一级动力学反应,反应的活化能为Ea=71.09052 kJ/mol. 根据化学动力学研究结果得到了在弱碱性条件下IPHA具有与水中游离氧反应速度快、反应所需活化能低等特点,进一步证实了IPHA具有良好的还原性.     

HCl-强酸性树脂催化合成DPA的工艺研究

研究了以C6H5OH和新型平台化合物乙酰丙酸(LA)为原料,采用HCl-强酸性树脂为催化剂、巯基乙酸为助催化剂催化合成高分子材料单体双酚酸(DPA)的合成工艺。考察了反应物料配比、催化剂中强酸性树脂的用量、反应温度、反应时间对DPA产率的影响。研究结果表明,在巯基乙酸作为助催化剂的条件下进行LA和C6H5OH的缩合,最佳工艺条件为:反应物料配比为n(C6H5OH)∶n(LA)=4∶1,强酸性树脂为15 g,反应温度60℃,反应时间40 h。在该条件下,DPA的产率为62%。     

戊基环己基苯甲酸的合成

环己烯与戊酰氯在常温下混合均匀后 ,与苯反应生成戊酰基环己基苯 ,再经Wolff-Kishner-黄鸣龙还原反应及氯仿反应得到戊基环己基苯甲酸。本文着重对戊酰基环己基苯的合成进行了改进。     

Determination of the kinetics of chlorobenzene nitration using a homogeneously continuous microflow

The nitration of chlorobenzene with concentrated mixed acids is a fast and highly exothermic process, which suffers from considerable mass transfer resistance and poor heat transfer rates. The reaction kinetics has not been thoroughly reported before. In this work, a continuous-flow microreactor system and a homogeneous reaction condition were proposed to obtain accurate chlorobenzene nitration kinetics parameters at high mixed acid concentrations. A general model for predicting the observed reaction rate constants was established. With a new method for estimating the equilibria associated with HNO₃ in aqueous sulfuric acid, the rate constants based on nitronium ion and activation energies were obtained. Compared with batch reactors, the continuous-flow microreactor system allows for a sufficient heat transfer efficiency and accurate residence time control, making it possible to study the reaction performance more quickly and sensitively. This work may provide a reliable reference for the kinetic study of similar processes.     

金属-有机框架材料在硅氢加成反应中的应用研究进展

硅氢加成反应是指在一定条件下含有硅氢键的化合物与含不饱和键的化合物进行的加成反应，是构筑C—Si键的重要反应之一，在有机硅工业中具有举足轻重的地位。该文综述了近年来金属-有机框架（MOFs）材料催化不饱和烃、羰基化合物和CO2的硅氢加成反应的研究进展，并针对每一种反应底物进行系统地总结与评述，最后指出了MOFs材料用于催化硅氢加成反应存在的问题，并对其未来发展方向进行了展望。