共查询到20条相似文献,搜索用时 93 毫秒
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硝化反应是一种十分重要的有机反应,在化工领域较为常见.近年来,我国的化工产业得到了快速的发展,同时也对企业日常硝化反应相关工艺提出了越来越高的要求.近年来,由于环境污染问题日益为各国关注,在化工领域,各种具有安全、环境污染少等特点的绿色硝化剂颇受重视.五氧化二氮是近年来备受关注的一种绿色硝化剂,主要对绿色硝化剂五氧化二... 相似文献
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短程硝化反硝化技术是将硝化反应控制在亚硝酸盐阶段,不进行亚硝酸盐至硝酸盐的转化,直接进行反硝化反应。文章阐述了短程硝化反硝化的形成机理,理论研究进展,系统介绍了短程硝化反硝化影响因素与控制分析,并探讨了短程硝化反硝化生物脱氮技术需深入研究的要点 相似文献
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推荐一种新硝化剂五氧化二氮及其工业化的生产方法 总被引:3,自引:0,他引:3
硝化是化学工业广泛应用的反应,但常规硝化剂是由浓硝酸和浓硫酸混成的,它是一种非常落后且危险性很大的硝化剂。五氧化二氧硝化剂比常规混合酸硝化剂有五大优点,因为它可用半渗透膜电解池法制造,所以今天五氧化二氮商品可以由工业化装置生产,建议国内各浓硝酸生产结合各自工艺特长创造发展新硝化剂生产。 相似文献
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短程硝化反硝化生物脱氮 总被引:1,自引:0,他引:1
对传统的完全硝化反硝化脱氮工艺和短程硝化反硝化的脱氮工艺进行了比较,分析了短程硝化反硝化脱氮工艺的优缺点以及要实现短程硝化反硝化所需要的条件,并介绍了一些国内外研究学者在这方面的研究进展,探讨实现短程硝化反硝化的工艺参数控制以及在实际工程应用中豹价值。 相似文献
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对采用臭氧介质二氧化氮体系作为硝化剂的一种绿色硝化技术做了综述,对该硝化体系的特点和原理进行了分析,并结合对某些芳烃化合物的硝化过程,提出了其作为新型清洁硝化剂的优缺点。 相似文献
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《Propellants, Explosives, Pyrotechnics》2017,42(2):220-223
The synthesis of n‐BuNENA by reaction of N‐butylethanolamine and thionyl nitrate is reported herein. Various nitrating agents were studied and thionyl nitrate was found to be a promising nitrating agent. The reaction conditions for the nitration with thionyl nitrate were optimized and the best results were obtained with one equivalent of thionyl nitrate at 0 °C for 3 h. This method has a number of advantages such as performing the reaction in one step, easy handling and work‐up, and good yield. The reaction progress was monitored by HPLC and the product was characterized by IR and 1H NMR spectroscopy. 相似文献
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Pawe Maksimowski Maciej Duda Waldemar Tomaszewski 《Propellants, Explosives, Pyrotechnics》2011,36(4):320-326
2‐Acetyl‐4,6,8,10,12‐pentanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (PNAIW) is formed in the last step of nitration of acetyl isowurtzitane derivatives. The amount of the PNAIW formed depends on the conditions of the nitration reaction (temperature, time, and nitrating mixture used) and on the type of the starting acetyl intermediate. The highest PNAIW yields (30 %) were obtained by nitrating 2,6,8,12‐tetraacetylhexaazaisowurtzitane (TAIW) at 60 °C for half an hour using HNO3/H2SO4 nitrating mixture. HPLC, NMR, FTIR, and DSC measurements were used in the study and their results are reported. 相似文献
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研究了磷酸二氢钠催化甲苯硝化反应的催化活性,通过气相色谱考察了催化剂用量、反应时间、硝化反应温度及催化剂的重复使用等因素对甲苯转化率和产物区域选择性的影响。实验结果表明,在醋酐存在条件下,以CCl4为溶剂,质量分数为95%的硝酸为硝化剂,反应温度55℃,反应60min,1.0g磷酸二氢钠为催化剂,甲苯硝化表现出强的区域选择性,甲苯硝化产物邻对位摩尔比达1.16,较硝硫混酸的1.67显著降低,产物得率达到100%。该催化剂循环使用5次后,催化活性变化很小,产率仅下降0.1%。 相似文献
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Nitration of aromatics is a key process in the catalytic manufacturing of semiproducts for the synthesis of drugs, pesticides, and dyes. However, the large-scale synthesis, involving the concentrated mineral acids used as catalysts, makes nitration one of the most environmentally harmful processes, producing huge amounts of organic wastes, exhausted acids, and the products of their neutralization. A search for environmentally safer catalysts and nitrating agents appears to be an actuality. Numerous data concerning the aromatics nitration in homogeneous media have been summarized in a set of books and reviews [l-41. Recent papers are of considerable interest, since they reflect the attempts to perform nitration on heterogeneous catalysts, for example, zeolites [5–8]. The data on aromatic nitration on the surface of solid acids [9, 111 and in the gas phase [12–14] allowed us to clarify the role of intermediate Tand a-complexes, estimate the substrate and position selectivity, and elucidate the main approaches of nitration mechanism in various media. In this review the data concerning nitration on solid catalysts are summarized. We hope this information will make it possible to estimate the perspectives of heterogeneous catalyst application on a large scale. 相似文献
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张丽 《化学工业与工程技术》2013,(6):64-66
以Lewis酸作催化剂、硝酸作硝化剂进行氯苯硝化,主要产物是对硝基氯苯、邻硝基氯苯。对其硝化产物进行了定性分析,发现几乎不含间位及其他副产物。以硝基苯为内标物,采用多点校正作出了氯苯、对硝基氯苯、邻硝基氯苯的内标曲线,并对其准确度进行了验证,为氯苯硝化的研究找到一种简便、快捷的定量分析方法。 相似文献
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Electron spectroscopy for chemical analysis (ESCA) has been employed to follow the surface nitration of cellulose papers in nitric acid–water and nitric acid–dichloromethane mixes with the aim of: elucidating the identity of the nitrating species in these mixes and from comparison of surface and bulk degree of substitution (DOS) further understanding on the role that morphology plays in the nitration of cellulose in these mixes. In nitric acid, nitric acid–water and nitric acid–dichloromethane mixes, surface nitration was observed to be slow (cf. to that reported in mixed acids) and the concentration of nitronium ion was observed to be low (cf. to mixed acids). On the basis of these observations and from the results of kinetic experiments, reported herein, it is proposed that the nitronium ion, NO2+, is the important nitrating species of cellulose in these nitric acid mixes. Nitration in all but the most concentrated nitric acid–dichloromethane mixes produced equal surface and bulk DOS; however, nitration in pure nitric acid produced different surface and bulk DOS. The latter result implies that the heterogeneous nature of the nitration reaction can influence the DOS achieved. 相似文献