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《化学通报》2016,(5)
采用自制的连续流动反应装置,分别以2520及316L不锈钢管为反应器,对不同气体流量(20、30、40 m L/min)、不同壁温(700、750、800℃)、恒定反应时间(20min)条件下干馏瓦斯中丙烯组分在不同反应器内的积炭特性的实验结果表明,两种管壁上初始积炭温度范围分别为630~650℃及670~690℃;扫描电镜对积炭微观形态观察表明,管内积炭都以丝状炭和无定形炭为主;程序升温氧化方法对不同工况下两种反应管内积炭量分析得出,316L耐热合金具有抗金属粉化特性;热重及差示扫描量热法对管内剥离炭样活性的表征结果证实,316L耐热合金内积炭活性比2520耐热合金内的高。 相似文献
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制备了100%SAPO-34,30%SAPO-34和介孔-SAPO-34三种不同类型的SAPO-34分子筛催化剂,并采用氮吸附、扫描电镜、X射线衍射和红外光谱等方法对催化剂进行了表征.三种催化剂的微孔结构、比表面积和总酸最近似,但具有不同的催化剂组成和次级结构.以1-己烯裂解为模型反应考察了三种催化剂的催化活性.对于30%SAPO-34催化剂,由于添加了粘结剂.其外表面酸性和扩散性能下降,导致催化活性降低:100%SAPO-34催化剂则具有较好的催化性能:介孔 SAPO-34催化剂次级结构的存在使其失活较慢,从而提高了原料的转化率.详细讨论了1-己烯催化裂解制丙烯的活性和选择性曲线,以进一步说明催化剂组成和结构的影响. 相似文献
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不同条件下苯与丙烯烷基化反应的催化剂失活研究 总被引:1,自引:0,他引:1
对不同条件下苯与丙烯烷基化反应Hβ催化剂的寿命、失活催化剂的积炭量和积炭性质进行了研究。在5.7MPa下,随反应温度变化,反应介质在反应过程中所经历的相态变化不同,导致催化剂的寿命、失活催化剂的积炭量和积炭的性质也存在着较大差异。300℃时,反应介质处于接近于体系临界点的超临界相或高压液相状态,催化剂寿命最长,积炭量大。失活催化剂积炭的元素分析及TPO-MS表征结果发现,积炭的碳氢比与反应温度有关,温度越高,碳氢比越高;而积炭的脱炭温度与反应时间(催化剂寿命)相关,催化剂寿命越长,相应的脱炭温度也越高。 相似文献
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重油催化裂解多产乙烯丙烯催化剂的研究 总被引:11,自引:2,他引:9
采用半合成法制备了不同金属改性的ZSM-5分子筛催化剂,以大庆VGO为原料,在固定床微型反应装置上对不同金属改性催化剂进行裂解生产低碳烯烃效果的评价,筛选出生产乙烯、丙烯性能较好的银+镧双金属改性催化剂,采用喷雾干燥的方法成型,并在800℃、100%水蒸气下老化处理4h。该催化剂在两段提升管实验装置上,以大庆AR为原料的评价结果表明,乙烯和丙烯收率可分别达到9.5%和24.9%;若考虑C4组分回炼,乙烯和丙烯收率可分别达到13.0%和29.9%。 相似文献
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Cu含量对Cu/Al-Ce-PILC上丙烯选择性催化还原NO反应的影响 总被引:3,自引:0,他引:3
采用聚合羟基复合阳离子合成交联粘土Al-Ce-PILC,经SO2-4改性后,以浸渍法制备了用于C3H6选择性还原NO反应的铜基交联粘土催化剂Cu/Al-Ce-PILC. 用XRD,XPS和TPR等技术对催化剂进行了表征,并考察了Cu含量对催化剂性能的影响. 结果表明,Cu负载未改变Al-Ce-PILC的结构; w(Cu)=2%时,Cu物种以Cu+和Cu2+两种形式存在,催化剂具有最高的催化活性和较宽的操作温度范围,在反应气组成为0.22%NO-0.12%C3H6-2.0%O2-97.66%He,空速为 24000 h-1和温度为350 ℃的条件下,NO转化率可达56.4%,700 ℃下仍可达22.3%; w(Cu)=5%时,催化剂中有明显的CuO物相存在,该物相促进C3H6的深度氧化,从而降低了NO选择性还原反应的性能. 相似文献
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对经过程序升温表面甲烷无氧芳构化反应(TPSR)后的Mo/HZSM-5催化剂上的积炭进行了程序升温加氢反应(TPH)和程序升温CO2反应(TPCO2),并对相应催化剂上的积炭进行了程序升温氧化反应(TPO)和热重(TG)实验.TPH实验及TPCO2实验表明,H2主要对高温烧炭峰发生作用.CO2则可同时对这两种烧炭峰产生影响,对低温峰积炭的影响尤其明显.对不同Mo含量的催化剂进行上述实验的结果表明,Mo担载量的变化及不同的实验过程都会影响催化剂上两种温峰的积炭在总积炭量中所占的比例.由TG实验数据计算出的动力学结果说明,无论是TPH还是TPCO2实验都可以降低烧炭过程的一级反应起始温度,并减少其活化能.此外,催化剂中Mo担载量的变化也会对开始温度和烧炭活化能产生明显影响. 相似文献
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反应条件对Cu/Al-Ce-PILC上丙烯选择性催化还原NO反应的影响 总被引:2,自引:0,他引:2
采用聚合羟基复合阳离子合成交联黏土Al-Ce-PILC, 经SO2-4改性后,以浸渍法制备了铜基交联黏土催化剂Cu/Al-Ce-PILC, 并将其应用于C3H6选择性还原NO的反应,考察了预处理气氛、 O2和C3H6浓度、空速、水蒸气和SO2等反应条件对催化剂性能的影响. 结果表明, He预处理后催化剂表面的Cu物种以Cu+和Cu2+两种形式存在,而H2预处理后仅以Cu+存在, NO转化率最大值由23%升至56%. 反应体系中适当的O2和C3H6浓度可促进NO还原为N2, 但过高的浓度反而可降低NO的还原活性, O2同时可起到抑制积炭、清洁催化剂表面的作用. NO转化率随着空速的增大而降低. 10%水蒸气的存在可抑制NO的还原和C3H6的氧化,其转化率曲线向高温方向位移. 但是,由于金属氧化物交联柱表面的疏水特性, Cu/Al-Ce-PILC较Cu/ZSM-5具有较强的耐湿热稳定性, NO和C3H6最大转化率仅分别下降13%和5%. SO2的存在明显抑制了催化剂的低温活性,但对高温活性有一定促进作用. 相似文献
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H. Barkia L. Belkbir S. A. A. Jayaweera 《Journal of Thermal Analysis and Calorimetry》2004,76(2):615-622
Thermal analysis has been used to determine the impact of heating on the decomposition reaction of two Moroccan oil shales
between ambient temperature and 500°C. During pyrolysis of raw oil shale, the residual organic matter (residual carbon) obtained
for both shales depends on the heating rate (5 to 40°C min-1). Three stages characterize the overall process: the concentration of carbonaceous residue decreases with increase of heating
rate, become stable around 12°C min-1 and continue to decrease at higher heating rates. Activation energies were determined using the Coats-Redfern method. Results
show a change in the reaction mechanism at around 350°C. Below this temperature, the activation energy was 41.3 kJ mol-1 for the decomposition of Timahdit, and 40.5 kJ mol-1 for Tarfaya shale. Above this temperature the respective values are 64.3 and 61.3 kJ mol-1. The reactivity of Timahdit and Tarfaya oil shale residual carbon prepared at 12°C min-1 was subject to a dynamic air atmosphere to determine their thermal behaviour. Residual carbon obtained from Tarfaya oil shale
is shown to be more reactive than that obtained from Timahdit oil shale.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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H. Barkia L. Belkbir S. A. A. Jayaweera 《Journal of Thermal Analysis and Calorimetry》2006,86(1):121-123
Residual carbons
from kerogen extracted from two Moroccan oil shales (from Timahdit and Tarfaya)
were oxidized in air. The oxidations were studied by isothermal thermogravimetry.
Several kinetic models for mechanisms of the reactions were tested to fit
the experimental data. Oxidation of the residual carbon derived from Timahdit
oil shale followed a two-third order reaction with an activation energy of
58.5 kJ mol–1, whilst that from Tarfaya oil
shale was a half order reaction with activation energy of 64.1 kJ mol–1. 相似文献
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在对家用微波炉改造基础上搭建了微波干燥实验台,研究了柳树河油页岩微波干燥特性及对热解特性的影响。结果表明,微波干燥所需的时间为传统干燥所需时间的20%;微波干燥速率要明显大于传统干燥速率;Page模型适用于描写柳树河油页岩微波干燥过程。微波干燥的油页岩同热风干燥后及原样油页岩的热解活化能随转化率的变化曲线基本一致,整体呈先上升后下降的趋势,在转化率为0.7时达到最大值;热解活化能在80~200 kJ/mol变动;微波干燥油页岩热解反应有机质分解段的活化能增加。 相似文献
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桦甸油页岩有机岩相特征及其富集特性 总被引:2,自引:0,他引:2
桦甸油页岩有机岩相特征及其富集特性 《燃料化学学报》2016,44(3):321-327
为了研究油页岩中有机组分结合特性对有机质分离富集的影响,利用薄片透射光、反射单偏光、反射荧光等煤岩学研究手段研究桦甸油页岩中有机组分的种类、含量及赋存状态,并利用两种密度分离手段研究油页岩中有机质的解离特性.结果表明,桦甸油页岩有机质的变质程度较低,有机显微组分以沥青质体为主,占85.8%,镜质组和惰质组含量较低;有机质与矿物结合紧密,形成有机-矿物复合体,密度分离方法对有机质与矿物质分离效果有限;浮沉实验小于1.40g/cm3密度级样品的热解失重量及失重速率均低于较高密度级产物,这与颗粒状镜质组、惰质组与矿物质结合程度相对较差,在较低密度级产物中富集有关. 相似文献
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Effects of acid treatments on Moroccan Tarfaya oil shale and pyrolysis of oil shale and their kerogen 总被引:3,自引:1,他引:3
In this study, the kerogen of oil shale from Moroccan Tarfaya deposits was isolated and the changes in the initial organic matter during the removal of the mineral matrix were examined. Chloroform extraction of the oil shale increases the intensity of the peaks in the X-ray diffractograms. Infrared spectra and X-ray diffractograms reveal the presence of mineral, calcite, quartz, kaolinite, and pyrite in the mineral matrix of the oil shale. Hydrochloric and hydrofluoric acids dissolution do not alter the organic matter. The nonisothermal weight loss measurements indicate that thermal decomposition of the isolated kerogen can be described by firstorder reaction. A single kinetic expression is valid over the temperature range of kerogen pyrolysis between 433K and 873K. Furthermore, the results indicate that the removal of mineral matter causes a decrease in the activation energies of the pyrolysis reactions of oil shale. 相似文献
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X. M. Jiang Z. G. Cui X. X. Han H. L. Yu 《Journal of Thermal Analysis and Calorimetry》2006,85(3):761-764
Co-combustion experiments of mixture of Huadian
oil shale and Heshan coal with high sulphur content have been conducted using
a thermogravimetric analyzer. The effects of five different Ca/S mol ratios
on the combustion characteristics of mixture fuel are analyzed using TG and
DTG curves. The results show that the initial temperature of combustion of
mixture fuel is decreased with an increase in the oil shale content of mixture
fuel. The combustion characteristic of mixture fuel is superior to that of
Heshan coal. Adding about 20 mass% Huadian oil shale into Heshan coal is feasible
for desulfurization of mixture fuel during combustion. 相似文献
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Kök M. V. Pokol G. Keskin C. Madarász J. Bagci S. 《Journal of Thermal Analysis and Calorimetry》2004,76(1):247-254
In this research thermal analysis and kinetics of ten lignite's and two oil shale samples of different origin were performed
using a TA 2960 thermal analysis system with thermogravimetry (TG/DTG) and differential al analysis (DTA) modules. Experiments
were performed with a sample size of ~10 mg, heating rate of 10°C min-1. Flow rate was kept constant (10 L h-1) in the temperature range of 20-900°C. Mainly three different reaction regions were observed in most of the samples studied.
The first region was due to the evaporation of moisture in the sample. The second region was due to the release of volatile
matter and burning of carbon and called as primary reaction region. Third region was due to the decomposition of mineral matter
in samples studied. In kinetic calculations, oxidation of lignite and oil shale is described by first-order kinetics. Depending
on the characteristics of the samples, the activation energy values are varied and the results are discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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FLASHCHAIN模型应用于汪清油页岩热解研究 《燃料化学学报》2016,44(2):138-145
采用~(13)C-NMR技术表征出汪清三个矿区油页岩的碳原子化学结构,并获得碳骨架结构的12个重要参数。利用热重和傅里叶红外联用技术(TG-FTIR)得出了在50℃/min升温速率和热解终温600℃下油页岩热解时轻质气体的生成规律。采用基于燃料化学结构的FLASHCHAIN模型对热解产物的析出进行了模拟,并与实验结果相比较。结果表明,FLASHCHAIN模型用来模拟汪清油页岩热解时,在520℃之前有较好的效果,当温度高于520℃时,由于二次热解反应及页岩中矿物质分解对热解过程的影响,导致模型的预测值与实验值存在一定的误差,且随着温度的升高两者之间的误差也随之加大。 相似文献