Thermoanalytical Investigation of Some Binary Pyrotechnic Mixtures of Ammonium Azide as Chemical Gas Generating Systems

The conventional NaN₃/oxidants gas generator pyrotechnic mixtures suffer from leaving undesirable solid residues. The presented investigation aimed to overcome this problem through mixing of NH₄N₃ particles with some metallic components, and to introduce some new gas generator pyrotechnic mixtures. In this work, volatile ammonium azide particles were initially stabilized via microencapsulation technique, and blended with Zr, Ti, ZrH₂, and TiH₂ powders to produce different gas generation mixtures. Thermal properties and kinetic parameters of these pyrotechnic mixtures were investigated by using thermal analysis (TG/DTA and DSC) techniques. The apparent activation energy (E), ΔG^#, ΔH^#, ΔS^#, and critical ignition temperature (T_b) of the ignition processes of the mixtures were obtained from the DSC experiments. Among the investigated mixtures, NH₄N₃/ZrH₂ composition was found to show desirable efficiency, and also it can be considered as a safe pyrotechnic composition for gas generation property, due to its moderate ignition temperature.     

有机络合剂对锡与溴邻苯三酚红显色反应的影响

在pH1.60-2.10的氯乙酸缓冲溶液中和溴化十六烷基三甲基铵（CTMAB）存在下，锡（Ⅳ）与溴邻苯三酚红（BPR）形成1：2的红色络合物。该络合物的最大吸收波长为530nm，当有亚氨基二乙酸，磺基水杨酸或柠檬酸存在时，显色反应灵敏度明显提高。利用Sn(Ⅳ）-柠檬酸－BPR－CTMAB显色体系的分光光度法，对锰青铜合金和海军黄铜中锡的测定，结果令人满意。     

Studying the Influence of Alumina Catalysts Doped with Tin and Zinc Oxides in the Soybean Oil Pyrolysis Reaction

The pyrolysis of vegetable oils consists of cracking triglycerides to produce smaller molecules. A mixture of hydrocarbons and oxygenated compounds, such as carboxylic acids and aldehydes, is obtained as the product and which can be separated by fractional distillation. When the reaction is carried out in the absence of catalysts (thermal cracking), a great quantity of these oxygenated compounds is obtained. Thus, the presence of those oxygenated compounds in the products results in a high level of acidity, which can be a problem when using them as fuels in combustion engines. The aim of this work was to study the composition of the products obtained by cracking of vegetable oils assisted by γ-alumina doped with zinc and tin oxides. The products were analyzed by FT-IR, GC-MS and GC-FID and the acid number was determined by titration with alcoholic KOH solution. The acid number, infrared spectra and chromatograms of the resulting hydrocarbon mixtures indicated a significant reduction in oxygenated compounds when compared with the mixtures obtained by the thermal cracking process, thus decreasing the acidity of the mixture.     

原子荧光光度计测定水中锡的方法研究

对原子荧光光度计检测水中锡进行了研究,发现使用1%的盐酸做载流液,0.8%的硼氢化钾溶液做还原剂等检测条件下,其测定的精密度和准确性令人满意。     

Effect of Nano‐Copper Oxide and Copper Chromite on the Thermal Decomposition of Ammonium Perchlorate

The catalytic effect on the thermal decomposition behavior of ammonium perchlorate (AP) of p‐type nano‐CuO and CuCr₂O₄ synthesized by an electrochemical method has been investigated using differential scanning calorimetry as a function of catalyst concentration. The nano‐copper chromite (CuCr₂O₄) showed best catalytic effects as compared to nano‐cupric oxide (CuO) in lowering the high temperature decomposition by 118 °C at 2 wt.‐%. High heat releases of 5.430 and 3.921 kJ g⁻¹ were observed in the presence of nano‐CuO and CuCr₂O₄, respectively. The kinetic parameters were evaluated using the Kissinger method. The decrease in the activation energy and the increase in the rate constant for both the oxides confirmed the enhancement in catalytic activity of AP. A mechanism based on an electron transfer process has also been proposed for AP in the presence of nano‐metal oxides.     

Experimental Investigation on the Characteristics of Polyethylene Glycol/Cement Composites as Thermal Energy Storage Materials

The polyethylene glycol/cement composites as thermal energy storage materials were prepared by blending polyethylene glycol and cement. In composite materials, polyethylene glycol (PEG) is used as the phase change material for thermal energy storage and cement acts as the supporting material. A Fourier transformation infrared spectroscope (FT‐IR), x‐ray diffractometer (XRD), and scanning electronic microscope (SEM) were used to determine the chemical structure, the crystalloid phase, and microstructure of the polyethylene glycol/cement composites, respectively. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetry analyzer (TGA). The SEM results showed that the polyethylene glycol was well dispersed in the porous network of the cement.     

金属离子对DMC催化聚合聚醚制备反应的影响

研究了在双金属络合催化剂用于催化合成聚醚过程中 ,起始剂或催化剂可能带入的微量离子对聚合反应的影响。结果表明 ,金属离子是否使催化剂中毒与阴离子的种类有关。除ZnCl2以外 ,绝大部分盐酸盐均对催化反应起阻碍作用 ;不同的金属盐 ,使催化剂失活的能力有所不同 ,NaCl对催化剂的影响最大 ,当Na+质量分数为 3× 10 - 6 时 ,催化剂即失活 ,而Ca2 +和Mg2 +对催化剂的影响相对较小。硫酸盐对聚合反应的有害影响很小 ,而MgSO4 等有助催化作用     

硫酸脲分解磷矿反应机理探讨

以硫酸脲分解磷矿是一种新的N、P复肥生产方法,硫酸脲分解磷矿有其特殊的反应机理。利用在线显微摄像与物化分析相结合,可以很好地表征硫酸脲分解磷矿的反应机理。实验表明:硫酸脲与磷矿在液固接触的界面微区进行反应,反应微区内有离解、反应、结晶、复合等过程,并伴随有晶型转变。反应生成的硫酸钙晶体复盖反应粒子表面,形成包裹层增大传质阻力。反应物质通过CaSO40.5H2O晶膜的传递阻力是影响整个反应过程的重要因素。     

Validation of a Solid Oxide Fuel Cell Model on the International Energy Agency Benchmark Case with Hydrogen Fuel

A detailed model of a solid oxide fuel cell was developed with an object‐oriented open‐source computational fluid dynamics code based on a finite‐volume method. The methodology is derived from a local Nernst equation with associated irreversible losses. Calculations were performed with the International Energy Agency benchmark case #1 with hydrogen as fuel, for co‐flow, counter‐flow, and cross‐flow. While agreement with the results of previous workers was satisfactory, a number of shortcomings with the benchmark case were identified and highlighted. These include over‐simplified electro‐chemical kinetics, neglect of porous transport layers, and ambiguities associated with the very low flow rates prescribed for the benchmark case.     

多酚氧化酶催化单宁的氧化聚合反应研究

研究了多酚氧化酶催化单宁的氧化聚合反应情况 ,探索了反应条件及 7种化合物对酶活性的抑制效果 ,对产物进行了红外光谱和紫外光谱测试 ,相对粘度法测定了产物的分子量。结果表明 ,反应的最佳条件是pH为 5 .2 9,温度为 3 0℃ ,在所用抑制剂中 ,硫酸铜的抑制作用最强 ,与单宁酸的IR图相比 ,产物的 -OH吸收带变窄 ,在 12 60cm-1处吸收峰增强 ,而紫外吸收无变化。产物平均分子量为 3 5 41,说明多酚氧化酶能催化单宁的氧化聚合     

我国利用天然气发展分布式能源技术的探讨

介绍了分布式能源技术的基本概念和主要特点。结合我国的天然气利用状况提出了分布式能源技术推广应用的差别化政策和相关建议。     

Application of electrochemical techniques to study the effect on the anticorrosive properties of the addition of ytterbium and erbium triflates as catalysts on a powder epoxy network

New low curing temperature epoxy powder coatings cured with o-tolylbiguanide and catalyzed by the use of erbium(III) and ytterbium(III) trifluoromethanesulfonates have been formulated. Their curing kinetics and anticorrosive properties have been studied and compared with a system commonly used in industry (o-tolylbiguanide/epoxy resin). Three different tests for measuring anticorrosive properties (EIS, AC/DC/AC, and salt fog spray) have been used together with an adherence test, in order to establish the ideal system. Results show that a system using 1 phr of ytterbium triflate presents good anticorrosive properties. The technique AC/DC/AC has shown its ability to evaluate properly and much faster than other techniques the anticorrosive properties of powder coatings with similar results.     

Investigation on the polyamide 6/organoclay nanocomposites with or without a maleated polyolefin elastomer as a toughener

Polyamide 6 (PA 6)-based nanocomposites were prepared using a melt-mixing technique in this study. One commercial organoclay (denoted 30B) and one maleated polyolefin elastomer (denoted POEMA) served as the reinforcing filler and toughener, respectively. The X-ray diffraction (XRD), scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS) and transmission electron microscopy (TEM) results confirmed the nano-scaled dispersion of 30B in the composites. Different mixing sequences presented similar phase morphology for the same formulated nanocomposites. XRD results also revealed that both 30B and POEMA would induce the formation of γ form PA 6 crystal, with 30B exhibiting a higher efficiency. Differential scanning calorimetry (DSC) results indicated that the addition of 30B altered the crystallization kinetics of PA 6, which was mainly attributed to the prevailing formation of γ form crystal. Complex melting behaviors were observed for neat PA 6 and the nanocomposites. These complex behaviors are associated with different polymorphs and the ‘melting-recrystallization-remelting’ phenomenon. Moderate thermal stability enhancement of PA 6 after adding 30B and/or POEMA was confirmed using thermogravimetric analysis (TGA). The storage modulus, Young's modulus and tensile strength of PA 6 were increased after adding 30B. However, these properties declined after further incorporation of POEMA. The different-processed PA 6/30B/POEMA nanocomposites displayed balanced tensile properties and toughness between those of neat PA 6 and PA 6/30B nanocomposite.     

辅酶NADH模型物BNAH与活化烯烃在氧气饱和混合溶剂中的反应机理研究

在氧气饱和的混合溶剂中,随着反应时间的延长,在辅酶NADH模型物BNAH与活化烯烃的反应中,氧化产物与还原产物的比例逐渐变小,但总产率越来越大。     

Investigation on the Polyamide 6/SEBS-g-MA/Organoclay Nanocomposites with Glycidyl Methacrylate as a Compatibilizer

Polyamide 6 (PA6)/maleated styrene-ethylene/butadiene-styrene copolymers (SEBS-g-MA)/organoclay (DK5) composites with glycidyl methacrylate (GMA) as a compatibilizer were prepared by melt compounding. The influences of maleating, DK5 and GMA on interfacial adhesion and mechanical properties of PA6 composites were investigated in terms of SEM observations, mechanical testing, Molau tests, IR analyses, and rheological behavior. Satisfactorily balanced mechanical properties of the composite could be achieved in the presence of GMA. Both DK5 and GMA retarded the crystallization of PA6. The storage modulus, loss modulus, and complex viscosity of the composites were obviously affected by the addition of DK5 and GMA.     

固定流化床中N_2O一步氧化苯制苯酚的工艺条件研究

采用固定流化床反应器,研究了工艺条件对N20一步氧化苯制苯酚反应及Fe-ZSM-5分子筛催化剂性能的影响.在固定流化床反应器性能考察的基础上,以单因素实验法系统考察了温度(300～500℃)、原料苯/N_2O物质的量比(4:1～16:1)和操作气速(0.040～0.072 m/s)等对反应过程的影响;并基于单因素实验结果,采用L9(34)正交实验设计,综合考察了温度、原料苯/N_2O物质的量之比和操作气速对N_2O一步氧化苯制苯酚反应过程规律及产物分布的影响.以苯酚收率最大为目标函数最终确定的相对适宜工艺条件为:温度430℃,原料苯/N_2O摩尔物质的量之比9:1,操作气速0.050 m/s.在此条件下,苯酚的收率可达71.32%.     

EMMS-based Eulerian simulation on the hydrodynamics of a bubbling fluidized bed with FCC particles

Although great progress has been made in modeling the bubbling fluidization of Geldart B and D particles using standard Eulerian approach, recent studies have shown that suitable sub-grid scale models should be introduced to improve the simulation on the hydrodynamics of Geldart A particles. In this study, the flow structures inside a bubbling fluidized bed of FCC particles are simulated in an Eulerian approach employing the energy minimization multi-scale (EMMS) model (Chemical Engineering Science, 2008, 63: 1553-1571) as the sub-grid scale model for effective inter-phase drag force, using an implicit cluster diameter expression. It was shown that the experimentally found axial and radial solid concentration profiles and radial particle velocity profiles can be well reproduced.     

20kt/a硫磺回收装置开工运行技术分析

中国石油吉林石化公司炼油厂20 kt/a硫磺回收联合装置为千万吨炼油项目工程中的配套环保装置,是炼油厂第二套硫磺回收装置,装置于2010年5月18日投料开工一次成功。介绍了装置的工艺流程、工艺原理及开工运行情况,对装置开工运行中存在的主要问题进行了分析和总结。结果表明:20 kt/a硫磺回收联合装置自投产以来运行平稳,装置的主要技术指标达到设计标准,尾气中SO2排放满足国家大气污染物综合排放标准的要求。     

The influences of the gas rate dissolution and mass-transfer limitation at the interfaces on selectivity of gas–liquid processes in stirred reactors with a suspended catalyst

A complex mathematical model accounting for the hydrogen dissolution process in suspensions and mass-transfer steps at the liquid–solid interface for the gas and liquid components is given. The calculated data according to the model for the reaction A→B→C shows, that the yield of an intermediate product B is very much affected by the relation of the gas component mass-transfer coefficient on the gas–liquid interface to that on the liquid–solid one. The hydrogenation of chlornitroaromatic compounds was analysed. The kinetics of the catalytic reduction of p-chlornitrobenzene to p-chloraniline via corresponding arylhydroxilamine on the Ir/C catalyst experimentally in a batch reactor has been studied. In this process the first reactions depend on the hydrogen concentration but the second ones are not dependent — this is a disproportion of the intermediate product to the final product — amine.