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催化剂对煤着火特性的影响 Ⅱ.不同催化剂对煤催化着火的影响 总被引:10,自引:2,他引:8
通过测定煤的着火点研究了不同催化剂对大同烟煤和晋城无烟煤的催化着火的影响。结果表明,催化剂化学组成是决定催化作用大小的一个重要的因素,具有同一碱金属离子,不同阴离子的催化剂酸性越强,催化作用越弱,其催化活性顺序为OH~->CO_3~(2-)>Cl~->SO_4~(2-);具有同一阴离子,不同碱金属或碱土金属阳离子的催化作用可用“电子转移学说”来解释,其催化作用的大小,随相应的碱金属,碱土金属的第一电离能的减少而增加。 相似文献
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催化剂对煤着火特性的影响Ⅰ.煤性质及煤中矿物质对煤催化着火的影响 总被引:5,自引:0,他引:5
使用可在加压下测定着火点的装置,研究了煤化程度、煤中太物质和煤焦干馏温度对煤或煤焦的催化着火的影响。结果表明,对于煤的催化着火来说,煤化程度、煤焦干馏温度仍是影响煤或煤焦活性的重要因素,但是添加催化剂后,煤的活性顺序也发生了一定的变化;煤中矿物有一定的催化着火作用,催化作用的大小与煤中钙、钾、钠含量及其存在形态、分布状况有关;催化作用的大小与催化剂添加量有关,并且添加量存在一个最佳值,此时着火点最 低。 相似文献
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VPO催化剂的再生性质及其对晶格氧选择氧化丙烷的影响 总被引:2,自引:0,他引:2
采用脉冲反应器,研究了VPO催化剂的再生性质及其对晶格氧选择氧化丙烷制丙烯酸和乙酸的影响,结果表明,VPO催化剂与气相分子氧反应的速度要比丙烷与其 和氧反应的速度慢许多,因此以丙烷-O2共进料方式进行反应时,催化剂氧化再生是速度控制步骤,水是影响催化剂选择性的重要因素,但对活性影响不大,在反应温度下,水在VPO催化剂 为可逆吸附,容易脱附流失,催化丙烷反应生成目的的产物的活性中心很稳定,主要是晶格 相似文献
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载体对负载钯催化剂表面氧性质的影响 总被引:1,自引:0,他引:1
载体对负载钯催化剂表面氧性质的影响陈敏*罗孟飞袁贤鑫(杭州大学催化研究所杭州310028)关键词负载钯催化剂,氧物种1996-11-18收稿,1997-05-28修回工业生产排放的有机废气和汽车尾气是大气污染的主要因素.用催化燃烧处理有机废气是环境保... 相似文献
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应用TG-FTIR联用研究催化剂对煤热解的影响 总被引:10,自引:3,他引:7
用TG-FTIR联用技术研究了碱金属、碱土金属和过渡金属对宝日希勒褐煤和包头烟煤热解的催化作用和挥发分析出的影响。结果表明,各种催化剂对褐煤和烟煤热解的催化效果分别为Ni>Fe~Ca>K和Ca~Fe>Ni>K,K2CO3对煤的热解没有明显的催化作用。催化剂使褐煤和烟煤热解转化率增加的最大值分别为10.1%和6.4%。烟煤热解生成的CH4比褐煤的多,不同的催化剂使煤热解挥发产物CO2、H2O、CH4和CO增加的幅度不一样,催化效果与温度和煤的变质程度有关。 相似文献
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利用1-甲基萘(1-MN)对先锋褐煤进行热溶,并在温和条件下分别对原煤及其热溶残煤进行过氧化氢氧化。结合元素分析和FT-IR对各级产物进行结构表征,用GC/MS对氧化反应水溶性产物的甲酯化衍生物进行分析。结果表明,先锋褐煤在1-MN中的热溶率较低,320 ℃下热溶残煤(TR)的收率为81.01%,该煤主要以共价键交联的大分子结构为主,非共价键缔合的小分子含量较低,并以脂肪结构为主,含一定量的羰基以及少量的羟基和芳香结构。原煤和热溶残煤氧化水溶性产物中α,ω-二羧基烷酸含量较高,同时还发现,相当含量的芳香酸及三元羧酸存在,其中,α,ω-二羧基烷酸主要以丙二酸和丁二酸为主;原煤中可溶小分子易被氧化并生成较复杂的产物。与原煤相比,热溶残煤结构更为规整,氧化主要以共价键交联的大分子结构的氧化解聚为主,氧解率较低,水溶性氧解产物也较简单,种类较少,据此推测先锋褐煤的桥键主要以为-CH2-和-CH2-CH2-为主。 相似文献
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丙烯酰胺合成中氧对还原铜催化剂性能的影响杨博,李晶明,周贵林,谢筱帆,李圭甲(中国科学院长春应用化学研究所长春130022)关键词丙烯腈,丙烯酰胺,铜催化剂,催比活性还原铜和Raney铜是丙烯腈水合合成丙烯酰胺的非常有效的催化剂,丙烯腈转化率可达10... 相似文献
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S. R. Garaeva Ahmet Alper Aydin Adnan Aydin Bahattin Yalçin P. A. Fatullaeva A. A. Medzhidov 《Russian Journal of Applied Chemistry》2010,83(1):97-101
Structure of products formed in polyethylene oxidation by nitric acid was studied by NMR, IR, and electronic absorption spectroscopies
and derivatography. 相似文献
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The degradation process that takes place at room temperature when bis(2,4,4-trimethylpentyl)monothiophosphinic acid (R2P(S)OH), bis(2,4,4-trimethylpentyl)dithiophosphinic acid (R2P(S)SH) and tris(2,4,4-trimethylpentyl)phosphine sulfide (R3PS) are in contact with 5 M HNO3 has been studied by FT-Infrared, FT-Raman spectroscopy and by gas chromatography with mass spectrometry detection (GC-MS). An exposure period of ten days of the rough reagents to 5 M HNO3 causes complete oxidation of the compounds. This process mainly leads to the formation of nitrogen dioxide, elemental sulfur and the oxo-analogues of the reagents. For dilute solutions of the reagents it was observed that after 15 min of contact with phase-shaking, R2P(S)OH and R3PS are completely oxidized to yield R2P(O)OH and R3PO, respectively, whereas for R2P(S)SH, the oxidation process is less severe, because the dithioacid is still present in the oxidized mixture, the oxidation products being R2P(S)OH and R2P(O)OH. 相似文献
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A. S. Morkovnik N. M. Dobaeva O. Yu. Okhlobystin 《Chemistry of Heterocyclic Compounds》1981,17(9):904-906
A phenothiazine cation radical, which was isolated preparatively in the form of the perchlorate in the reaction of phenothiazine with the minimum amount of nitric acid in aqueous perchloric acid, is formed initially in the nitration of phenothiazine with nitric acid to give 3-nitrophenothiazine S-oxide. The perchlorate is also converted to the nitro compound by nitration. During nitration the phenothiazine cation radical is oxidized to the phenazthioniuin cation, the perchlorate of which was also isolated preparatively in the reaction of phenothiazine with HNO3 in amounts that were twice the amount required for the formation of the phenothiazine cation radical. This is followed by the formation of the nitro derivative, which involves the reaction of the phenazthionium cation with the nitrite anion of nitrous acid. The resulting 3-nitrophenothiazine is then converted to the final product.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1214–1216, September, 1981. 相似文献
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N. S. Polyakov G. A. Petukhova F. Stoeckli T. Centeno A. Lavanchy 《Russian Chemical Bulletin》1996,45(5):1071-1077
The influence of oxidation by nitric acid on the character of oxygen-containing functional surface groups and porous structure of active carbons is considered. Adsorption properties of the initial and oxidized carbons are studied using adsorption isotherms of vapor of n-hexane and polar substances (water and methanol).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1132–1137, May, 1996. 相似文献
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Yu. G. Khabarov D. E. Lakhmanov D. S. Kosyakov N. V. Ul’yanovskii 《Russian Chemical Bulletin》2016,65(1):237-244
The properties of the reaction products of hydrolytic lignin with nitric acid in water—dioxane medium were studied. The products are a mixture of nitrogen-containing oligomeric compounds with high degree of polydispersity. 相似文献
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逐级酸处理对锡盟褐煤的结构及热解特性的影响 总被引:1,自引:0,他引:1
为了探讨高硫褐煤提质利用中酸洗处理对煤质特性的影响,以内蒙古锡盟褐煤为研究对象,依次用HF、HNO3和HCl的酸溶液进行预处理,对原煤及其酸处理样品进行了傅里叶变换红外光谱的煤结构表征、程序升温差热-热重实验的煤热解特性研究及其反应过程的动力学分析。结果表明,HF处理对煤样的结构影响不大,HNO3的处理明显改变了HF处理后煤样中有机质的结构,HCl处理又使HNO3处理引起的煤样中脂肪基团CH3的吸收峰强度变化减弱;逐级酸处理对锡盟褐煤的热解特性存在一定的影响,HF和HNO3处理对褐煤的热解反应性具有促进作用,HCl处理对其热解反应性的影响不大。动力学分析显示,不同过程酸预处理对褐煤热解过程的影响不能单独采用热解过程的总包反应活化能进行描述,热解活化能不仅与指前因子存在着补偿效应,也与热解阶段的失重量存在一定的关联。 相似文献
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A mathematical model for the thermal oxidation of coal in a pseudo-fluidized catalyst bed is suggested. A three-phase system: catalyst, gas and coal, is considered. The boundary conditions for the pulse operation of the reactor are discussed.
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Robert Pietrzak Helena Wachowska Piotr Nowicki 《Central European Journal of Chemistry》2005,3(4):852-865
Solid and soluble products of THF and CH2Cl2 extraction of flame coal oxidised by four different oxidising agents (peroxyacetic acid (PAA), 5% HNO3, O2/Na2CO3, air/125 °C) were studied by elemental analysis and FTIR. The extraction yield with THF was much higher than that with CH2Cl2 for all samples. The greatest changes in elemental composition were in the extracts from coal oxidised by nitric acid. The
sulphur content was lowest in extracts from coal oxidised with 5% HNO3 and PAA. FTIR confirmed that coal treatment with nitric acid incorporates nitrogen into the coal structure. 相似文献
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The kinetics of acetamidotoluene oxidation in glacial acetic acid in the presence of cobalt acetate is reported. At 95°C and
atmospheric pressure, acetamidotoluenes are oxidized by molecular oxygen very slowly: oxidation is complete in 10–12 h, and
the major reaction products are acetamidobenzoic acids (27–36% yield). The introduction of ozone into the reactive gas increases
the reaction rate by one order of magnitude. The main role of ozone is to generate the active form of the catalyst. 相似文献