Measurement of Gibbs energies of formation of CoF2 and MnF2 using a new composite dispersed solid electrolyte

Gibbs energies of formation of CoF₂ and MnF₂ have been measured in the temperature range from 700 to 1100 K using Al₂O₃-dispersed CaF₂ solid electrolyte and Ni+NiF₂ as the reference electrode. The dispersed solid electrolyte has higher conductivity than pure CaF₂ thus permitting accurate measurements at lower temperatures. However, to prevent reaction between Al₂O₃ in the solid electrolyte and NiF₂ (or CoF₂) at the electrode, the dispersed solid electrolyte was coated with pure CaF₂, thus creating a composite structure. The free energies of formation of CoF₂ and MnF₂ are (± 1700) J mol⁻¹; {fx37-1} The third law analysis gives the enthalpy of formation of solid CoF₂ as ΔH° (298·15 K) = −672·69 (± 0·1) kJ mol⁻¹, which compares with a value of −671·5 (± 4) kJ mol⁻¹ given in Janaf tables. For solid MnF₂, ΔH°(298·15 K) = − 854·97 (± 0·13) kJ mol⁻¹, which is significantly different from a value of −803·3 kJ mol⁻¹ given in the compilation by Barinet al.     

Monoacylglycerols derived from butter oil by Penicillium roquefortii in suspension cultures

Structural isomers of monoacylglycerols (monoglycerides, MAGs) were identified and compared after degradation of butter oil by two strains of Penicillium roquefortii and a commercial lipase from P roquefortii (EC 3.1.1.3) at pH 7.0 and 10 °C. The conditions were selected as they were comparable with those used in the manufacture of blue mould‐ripened cheese. The commercial lipase was selected to compare with the fungal strains in terms of acyl migration. Results showed that the main isomers formed by lipolysis with the commercial lipase were sn‐2 MAGs (64 mol%), whilst spores and emerging mycelia of P roquefortii produced mainly sn‐1(3) MAGs (83–90 mol%). The work reported here may lead to further assessment of different MAG structural isomers as natural preservatives in foods and dairy products. © 2002 Society of Chemical Industry     

负压法(射流法)回收治理液氨尾气

论述了负压法(射流法)回收治理液氨尾气的环保安全工艺技术、原理；解决了目前一直沿用的正压法无法解决的棘手问题。     

合成氨扩能改造中锅炉存在的问题及采取的措施

针对天脊集团年产30万t合成氨扩能改造,给2台225t/h高压锅炉带来的除氧器热量过剩、锅炉给水温度升高、主蒸汽温度降低等一系列问题,分析了产生问题的原因,从节约能源、提高锅炉效率考虑,提出了相应的解决问题的办法:利用热量分流、改造省煤器管、增加二级过热器受热面积。经过3年多的生产实践证明,取得了良好的效果。     

A new efficient method for one‐pot conversions of aryl carboxylic acids into nitriles without solvent

A new efficient method for synthesising nitriles, important organic reagents, is reported in this paper. In an environmentally benign solvent‐free system, aryl carboxylic acids were converted into the corresponding nitriles via one‐pot reactions, by amidation with ethyl carbamate followed by dehydration with thionyl chloride, in excellent yields. The results showed that the method has the advantages of lower cost, higher yield, less pollution and greater ease of work‐up. Copyright © 2008 Society of Chemical Industry     

聚丙烯酸酯/醇酸树脂复合乳液的合成与表征

用乳液聚合法合成了聚丙烯酸酯/醇酸树脂复合乳液,研究了醇酸树脂组成和用量及聚合条件对动力学和复合乳液性能的影响。结果表明,醇酸树脂对乳液聚合有明显的阻聚作用,而且这种阻聚作用随醇酸树脂中马来酸酐含量的增加而加剧。升高聚合温度和增加引发剂用量均有利于改善乳液的机械稳定性。随着醇酸树脂用量的增加,复合乳液的机械稳定性和涂膜的耐水性逐渐提高;醇酸树脂中马来酸酐含量增加,乳液机械稳定性提高,当醇酸树脂中马来酸酐质量分数为2 4%时,涂膜具有最佳的耐水性。     

Phase behavior of ternary blends containing dimethylpolycarbonate,tetramethylpolycarbonate and poly[styrene‐co‐(methyl methacrylate)] copolymers (or polystyrene)

The miscibility and phase behavior of ternary blends containing dimethylpolycarbonate (DMPC), tetramethylpolycarbonate (TMPC) and poly[styrene‐co‐(methyl methacrylate)] copolymer (SMMA) have been explored. Ternary blends containing polystyrene (PS) instead of SMMA were also examined. Blends of DMPC with SMMA copolymers (or PS) did not form miscible blends regardless of methyl methacrylate (MMA) content in copolymers. However, DMPC blends with SMMA (or PS) blends become miscible by adding TMPC. The miscible region of ternary blends is compared with the previously determined miscibility region of binary blends having the same chemical components and compositions. The region where the ternary blends are miscible is much narrower than that of binary blends. Based on lattice fluid theory, the observed phase behavior of ternary blends was analyzed. Even though the term representing the Gibbs free energy change of mixing for certain ternary blends had a negative value, blends were immiscible. It was revealed that a negative value of the Gibbs free energy change of mixing was not a sufficient condition for miscible ternary blends because of the asymmetry in the binary interactions involved in ternary blends. Copyright © 2004 Society of Chemical Industry     

High char‐yielding poly[acrylonitrile‐co‐(itaconic acid)‐co‐(methyl acrylate)]: synthesis and properties

Polyacrylonitrile terpolymers of various compositions consisting of acrylonitrile (AN), itaconic acid (IA) and methyl acrylate (MA) were synthesized by solution polymerization in dimethylsulfoxide. Increase in concentration of either IA or MA retarded the overall polymerization rate and the polymer molecular weight. The system consisting of AN + MA and varying IA concentration was more prone to retardation in comparison with the system composed of AN + IA with variable MA concentration. The retardation factors were quantified. Minor quantities of MA boost the reactivity of IA in the terpolymer system. The terpolymer was richer in MA vis‐à‐vis the feed. The thermal characteristics of the terpolymer were examined as a function of its composition. In contrast to the copolymer of AN and IA requiring 1–1.5 mol% IA, the terpolymer required an IA content of approximately 2.5 mol% for optimum thermal stability. The polymer with 90 mol% AN, 2.5 mol% IA and 7.5 mol% MA exhibited reasonably good char‐forming characteristics and thermal stability. The overall crystallinity and crystallite size of the polymers were found to decrease on incorporation of the comonomers. The ‘aromatization index’ of the copolymer increased with the temperature of pyrolysis through re‐organization of the tetrahydropyridine ladder structure. Copyright © 2005 Society of Chemical Industry     

液化天然气供气站的工艺设计

〗LNG供气站的设计核心是工艺设计，设计中应注意以下几点：正确处理技术先进性与经济合理性的关系，综合权衡设置费与运营费的比例，力求项目全寿命费用最低；大多数城市LNG供气站均利用空气气化LNG，单罐容积为100 m³的真空压力式储罐广泛用于储存量为1200 m³以下的LNG供气站；为正确设置储罐安全阀的开启压力和排放压力，必须根据储罐的最高工作压力按照规范正确确定储罐的设计压力；储罐上2套独立的液位计和高、低限报警自动切断装置可确保储罐安全运行；空温式气化器的气化能力按用气城市高峰小时计算流量的1.3~1.5倍确定，为便于自然化霜应设置2套空温式气化器切换使用；空温式气化器出口串接水浴式加热器可提高冬季或雨天出口天然气温度，保护碳钢管道并降低供销差；LNG储罐区应设置围堰，消防用水量为喷淋与水枪用水量之和。最后建议，必须尽快颁布国家LNG设计规范，以提高我国的LNG设计水平。     

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本文应用天然气中甲烷、乙烷的碳同位素,甲烷的氢同位素,汞含量及天然气成分等指标,探讨了四川盆地天然气成因分类;并结合地质情况对气源层进行了探讨。