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论述了苯胺加氢制环己胺的反应机理,对于液相加氢和气相加氢催化剂作了详细的介绍,指出非贵金属的气相加氢催化剂是今后的研究重点。 相似文献
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介绍了苯胺催化加氢制环己胺的技术概况,对各工艺的优缺点进行了评述,并叙述了苯胺催化加氢制环己胺催化剂的发展情况。 相似文献
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硝基苯液相催化加氢制苯胺催化剂研究进展 总被引:2,自引:1,他引:1
介绍了苯胺生产中硝基苯液相催化加氢制苯胺工艺,着重介绍了液相加氢催化剂体系中的镍系催化剂和贵金属催化剂的研究进展。液相催化加氢多采用贵金属催化剂和高活性、制备工艺复杂的催化剂,生产成本较高,开发价廉、高效并能满足绿色化工要求的新型催化剂是今后工作的重点。 相似文献
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石家庄中冀正元化工有限公司新建的一套10kt/a环己胺装置,采用苯胺加氢法,同时副产二环己胺。环己胺装置由下列工序组成:苯胺加氢还原和环己胺精制。环己胺粗品生产完成后,含有水、苯胺、二环己胺等杂质,产品纯度无法满足下游企业的需求,必须经过精制提纯。通过初馏塔进行初馏,去除水等轻组分,然后经过精馏塔进行精馏,去除焦油等重组分。提纯后的产品质量要求依据国家标准或下游产品需求企业的要求。 相似文献
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4-氨基二苯胺的合成研究 总被引:3,自引:0,他引:3
采用二苯胺法,用复合骨架镍为催化剂,在中低压条件下加氢还原制备4-氨基二苯胺.文章对加氢反应进行了重点研究,考察了催化剂及其用量、温度、压力以及物料浓度对加氢反应的影响.优惠条件下的稳定性实验表明:催化剂活性稳定,加氢反应的转化率稳定在99.5%以上,4-氨基二苯胺的收率稳定在95%以上.该实验结果对开发4-氨基二苯胺新工艺具有重要意义. 相似文献
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采用气相色谱法,以热导检测测定,KOH+PEG-20M为固定液,Chromosobr。W.HP为担体分析苯胺常压加氢催化产物-二环己胺,准确度,精确度都较好。 相似文献
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徐善明 《现代塑料加工应用》2008,20(5)
应用管理学和市场营销学的基本原理和方法,深入分析我国聚丙烯工业的内部和外部环境、市场状况以及加入WTO后所面临的机遇与挑战.在此基础上,应用SWTO(态势分析法),确认出主要的优势和劣势、机会和威胁,对我国聚丙烯工业的国际竞争力进行结构化的综合分析. 相似文献
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局外点检测对于注重试验和数据采集的化学化工领域,其重要性不可忽视。结合化学化工的数据特点,对局外点检测方法的理论基础、应用需求、研究思路、技术关键和发展进程进行了综合分析。分别针对线性和非线性参变对象,概要介绍了当前适用的检测方法,包括各类判别标准、直接和间接方式、单个和多个局外点检测、经典和现代方法以及它们的优缺点和最新进展。最后展望了局外点检测方法的前景和发展方向。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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茚酮化合物广泛存在于许多天然产物中,这类化合物具有多种生理活性,是重要的有机合成中间体,广泛应用于医药、农药、染料的合成等。本文重点介绍了环化法合成茚酮化合物,其中分子内傅雷德尔-克瑞福斯(Friedel-Crafts)环化法是茚酮化合物的经典合成法,该法优点是技术成熟,后处理较简单,易于工业化,但该方法产生大量的含铝废液,对环境造成污染。同时,文章对近年来出现的新的茚酮化合物合成方法,如重排法、光化法等进行了对比讨论,新方法与经典合成法相比,具有条件温和、步骤少、产物纯度高等优点,但受到所用原材料等条件的限制,其工业化进程不易实现。通过对近十几年来茚酮化合物合成方法的系统化讨论,指出开发绿色环保、原子经济、易于工业化的新的茚酮化合物合成方法是今后研究的重点。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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三种絮凝剂除藻效果的比较 总被引:1,自引:0,他引:1
以合肥市环城河为研究对象,采用聚合氯化铝(PAC)、聚合氯化铝铁(PAFC)、聚合硫酸铝铁(PAFS)三种絮凝剂对该含藻水体进行强化混凝除藻、除浊的试验研究,考察了絮凝剂种类及添加量、水样的pH、助凝剂的种类以添加量等因素对强化混凝效果的影响。结果表明:在相同添加量时,聚合氯化铝的除藻、除浊效果最好,当添加量为27 mg/L时,叶绿素a的去除率为87.46%,浊度的去除率为92.74%,添加高分子助凝剂PAM、HCA对原水的浊度、叶绿素a有一定的去除效果,助凝剂与絮凝剂的配合使用可改善絮凝剂的的混凝去除效果,助凝剂PAM的效果较好,当PAM的投加量为2 mg/L时,叶绿素a的去除率可提高5.91%,浊度的去除率可提高1.70%。 相似文献
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A. A. Konnov 《Combustion, Explosion, and Shock Waves》2005,41(5):496-503
A simple phenomenological diffusive-thermal model of cellular instability of premixed flames of ternary mixtures is developed
and presented. The model shows that preferential diffusion can alter stoichiometry of the mixture, i.e., the ratio of the
fuel and oxidizer concentrations, and also its effective dilution by an inert. Key parameters of the model are estimated using
numerical modeling of burning velocities. Laminar burning velocities are calculated for hydrogen-oxygen-nitrogen, methane-oxygen-nitrogen,
and propane-oxygen-nitrogen mixtures. Conditions for the appearance of cellular instability in ternary mixtures are determined
and compared with experiments. In good agreement with experimental observations, the diffusive-thermal instability is predicted
in hydrogen flames with equivalence ratios φ ≲ 1.45, in lean methane flames with φ ≲ 1.02, and in rich propane flames with
φ ≳ 1.03. The magnitude of the change in the local flame velocity due to preferential diffusion is evaluated. It is demonstrated
that nitrogen diffuses faster than oxygen in hydrogen-air and methane-air flames, while oxygen diffuses faster than nitrogen
in flames of propane and other heavier hydrocarbons. In mixtures of air with propane or heavier hydrocarbons, the transition
between stable and unstable regimes is predicted in mixtures that are leaner than the mixture corresponding to the peak of
the burning velocity curve, in agreement with experimental observations.
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Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 14–22, September–October, 2005. 相似文献