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吸附剂表面性质对柴油碱性氮化物吸附脱除的影响 总被引:2,自引:2,他引:2
对硅胶、改性硅胶、活性白土和γ-Al2O3四种吸附剂进行柴油吸附脱除碱性氮化物试验以及BET分析和吡啶吸附红外分析。结果表明,室温下硅胶在拐点前的碱性氮化物吸附等温式为: ;改性硅胶吸附碱性氮化物的吸附等温式为: ;γ-Al2O3的碱性氮化物吸附等温式为: ;活性白土的碱性氮化物吸附等温式为: 。研究发现,吸附剂比表面积不是吸附脱除柴油碱性氮化物的主要影响因素,孔径小于3.5nm时会阻碍碱性氮化物在吸附剂表面的扩散,降低吸附剂吸附容量。碱性氮化物在吸附剂表面的吸附作用以化学吸附为主, 随着吸附剂表面酸中心增加,吸附剂对碱性氮化物的吸附容量增加。 相似文献
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采用静态H_2化学吸附法在选定压力下测定了不同测试条件下的Ni催化剂的金属分散度,通过H_2-TPR实验研究了Ni催化剂中Ni的氧化态,考察了还原温度、还原时间、抽真空时间和吸附温度对Ni催化剂的金属分散度的影响。H_2-TPR实验结果表明,Ni催化剂中含有两种氧化态Ni,分别在300,800℃下可被还原。静态H_2化学吸附法的实验结果表明,高还原温度和长还原时间会使Ni金属发生高温烧结;长时间抽真空可去除还原过程中残留在体系内和Ni金属表面物理吸附的H_2;H_2在Ni金属上的化学吸附不需经过高温活化即可发生。测试Ni催化剂的金属分散度的适宜条件为:还原温度650℃,还原时间1 h,抽真空时间大于16 h,吸附温度50℃。在此条件下,Ni催化剂的金属分散度为5.46%。 相似文献
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通过对钠基膨润土插层改性,制备不同改性剂含量和不同改性剂成分的有机膨润土,并以此为稠化剂制备润滑脂,考察润滑脂的锥入度和压力分油,研究改性过程的影响因素及其对润滑脂性能的影响规律。文章讨论了膨润土的改性过程和膨润土润滑脂的稠化机理。实验结果表明,随着改性剂添加量的增加,膨润土层间距增大,改性剂分子在膨润土层间区域的排列从双层平卧变化为倾斜双层结构。当改性剂分子在膨润土层间区域的排列方式为倾斜单层结构时,即改性剂添加量为120-140mmol/100g,润滑脂的性能最佳。十八烷基三甲基氯化铵和十六烷基三甲基氯化铵混合改性膨润土,制备得到膨润土润滑脂的稠化性能、胶体安定性、抗磨性能和减磨性能均得到提高,最佳混合摩尔比为1:1。 相似文献
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用氢吸附,TEM、TPD和TPSR等方法研究了含稀土铕或钇的铂催化剂的表面性质。在脉冲微反色谱装置上研究了甲基环戊烷和正庚烷在上述催化剂上的芳构化、异构化和氢解性能。实验结果表明,铂钇催化剂中铂的分散度和正庚烷反应的芳构化活性有对应的关系;稀土铕或钇并未改变铂催化剂表面固有的吸附中心性质,但改变了铂催化剂吸附氢的量。此外,在加压连续微反色谱装置上研究了不同反应条件对正庚烷在铂钇催化剂上反应的影响。 相似文献
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多孔介质表面润湿性对交联聚合物溶液封堵性质的影响 总被引:2,自引:0,他引:2
采用毛玻璃模型、砂填充管和人造岩心封堵实验,研究了多孔介质的表面润湿性对交联聚合物溶液(LPS)封堵性能的影响。结果表明,未经甲基硅油处理的毛玻璃模型注入4.5Vp(Vp—孔隙体积)的LPS后,体系压力明显上升,达到120kPa左右;经甲基硅油处理的毛玻璃模型注入10 Vp的LPS后,体系压力始终保持在比较低的水平(6~8kPa)。未经甲基硅油处理的填充砂管注入40 Vp的LPS后,体系压力达70kPa左右;经甲基硅油处理过的填充砂管注入80 Vp的LPS后,体系压力只达到18kPa,没有明显上升。岩心并联实验中,甲基硅油处理过岩心与未经甲基硅油处理的岩心相比, 注水时的出口液体流量明显降低, 但注LPS后的出口液体流量明显增加。这表明LPS具有选择性封堵性质,即易于封堵水润湿的多孔介质,而难于封堵油润湿的多孔介质。 相似文献
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以Al2O3为载体采用等体积分步浸渍法制备了NiMo/Al2O3催化剂,在固定床反应器上研究了在相对较低的温度(200℃)条件下,烯烃的加入对甲基叔丁基硫醚的加氢转化的影响。实验结果表明,烯烃与硫醚在催化剂表面发生竞争吸附,其加入对硫醚的转化有明显的抑制作用。采用SEM电镜,S、C元素分析和X射线光电子能谱对催化剂的表面组成及形态进行表征,发现烯烃使得催化剂表面出现明显的颗粒聚集和结块现象,积碳量增加;同时,导致Ni向催化剂的表面迁移,Mo4+/Mo6+比值减小,Ni 0/Ni 2+比值增大,这均在一定程度上减弱了催化剂的活性。 相似文献
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用硅烷偶联剂对硅胶表面进行氨基功能化,利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺-胺树状大分子(PAMAM-SG);利用红外光谱对PAMAM-SG的结构进行了表征,研究了溶液pH值、ρ(Ni2 )和温度对PAMAM-SG吸附Ni2 能力的影响。结果表明,带有氨基和酯基的PAMAM-SG吸附Ni2 的能力均受到溶液酸碱性的影响,确定的其溶液最佳pH值为4.0~7.0;PAMAM-SG吸附Ni2 的量随ρ(Ni2 )的增大而增加直至平衡,吸附速率随时间的延长而逐渐降低,随温度的升高而增大。在30℃时具有较好的吸附性能,吸附量最大值为38.54 mg/g,各代PAMAM-SG的吸附能力从大到小依次为1.0 G,2.0 G,1.5 G,0.5 G,0 G,-0.5 G。 相似文献
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采用水热离子交换法制备出Cu(Ⅱ)-Y分子筛,考察了交换条件对其离子交换性能和晶体结构的影响,并经过活化处理后制备出Cu(I)-Y分子筛吸附剂,对其汽油脱硫性能进行了研究.结果表明高温水热处理能够大幅度地提高Cu(Ⅱ)-Y分子筛的Cu含量,但温度过高会破坏其晶体结构;分子筛适宜的水热交换条件为Cu(NO3)2溶液浓度0.5
mol/L、固液比0.05、交换温度135℃、交换时间12 h;适宜的活化条件为在500℃的N2中焙烧6
h;在上述条件下制得的分子筛吸附剂对模型汽油在常压、室温、液体时空速为10
h-1时的饱和硫容量为8.61%(质量分数). 相似文献
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天然气-H_2O-CO_2转化制取合成甲醇原料气的研究 Ⅰ.反应条件对合成气组 总被引:4,自引:1,他引:4
用新研制的具有高抗结炭性能的负载型镍催化剂SYM-1,模拟工业用变温固定床,进行了CH4-H2O-CO2体系制取合成甲醇用合成气的实验。结果表明,该催化剂对CH4-H2O-CO2反应具有良好的催化活性,能够制得工业合成甲醇用的合成气。甲烷的转化率和产物CO含量随温度升高而增加,随压力增大而下降。其较佳的反应条件为:反应温度900℃;压力0.1~0.7MPa,甲烷空速500~1500h-1;原料配比CH4:H2O:CO2=1:(1.1~1.5):0.3。 相似文献
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《Egyptian Journal of Petroleum》2021,30(4):37-42
Further studies into drilling fluids especially to reduce the use of oil and synthetic-based drilling fluids are ever-growing due to their contributions to environmental pollution. This study, therefore, attempts to evaluate the thermal, viscosity, surface tension, and filtration loss properties of water-based drilling fluids (WBDFs) upon the addition of Gemini surfactant-silica nanofluid. This surfactant-nanofluid was formed by dissolving silica nanofluid in the surfactant solution, and ultra-sonication was used to attain homogeneity. Characterization of the Gemini surfactant-silica (SiO2) nanofluid was done by Fourier Transform Infrared Spectroscopy (FTIR). The viscosity, surface tension, and filtration loss properties were studied using the rheometer, tensiometer, and low-pressure, low-temperature (LPLT) filter press respectively. The experimental results showed that Gemini surfactants contributed to the highest increase in drilling fluid viscosity compared to a conventional surfactant. Also, when combined with silica-nanoparticles showed better thermal stability with an 11% average change in viscosity with increasing temperature and a decrease in surface tension and filtration loss both showing a 17% and 12% decrease respectively. 相似文献
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《Food Control》2017
The objective of this study was to evaluate the influence of surface properties of produce and food contact surfaces on the antimicrobial effect of chlorine dioxide (ClO2) gas against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes. The hydrophobicity of the selected surfaces was evaluated by water contact angle measurements. White light scanning interferometry (WLSI) was used to acquire surface roughness values of each surface. Produce and food contact surfaces inoculated with foodborne pathogens were treated with 20 ppmv ClO2 gas for 5, 10, and 15 min. As treatment time increased, different levels of inactivation of the three pathogens were observed among the samples. Contact angles of produce and food contact surfaces were highly and negatively correlated with the log reduction of all three pathogens. There were generally weaker correlations between the roughness values of sample surfaces and microbial reduction compared to those between hydrophobicity and microbial reduction. The results of this study showed that surface hydrophobicity is a more important factor relative to bacterial inactivation by ClO2 gas from the surface than is surface roughness. Also, the existence of crevices with features of similar size to the pathogen cell was more important than the Ra and Rq values in the inactivation of pathogens. 相似文献
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Shehdeh Jodeh 《化学与化工:英文版》2009,(10):7-17
This paper describes the conductivity modifications induced by heavy ion implantation in pyrolysis products obtained by thermal treatment of polyacrylonitrile (PAN) thin films at temperatures of 435℃ (PAN435) and 750℃ (PAN750) under vacuum. Ionic species having different chemical reactivities such as Kr, As, Cl. and F ions were utilized to allow interpretation of the conductivity' data either in terms of implantation induced molecular rearrangements or in terms of specific chemical doping effects. The temperature dependence of conductivity in the range between 25-3000C followed nearly a simple activation conduction relationship from which the temperature coefficients of resistivity (ct) were determined. In this temperature range, PAN750 provided the smallest α value compared with ion implanted PAN750 or with products obtained at the lower pyrolysis temperature. However. the corresponding lowest rate of conductivity change with temperatures (0.49%/℃) obtained in this study far exceeds the specification value required for thin film resistor applications (〈 0.1%/℃). 相似文献
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应用乌式粘度计和电导率仪,采用动态光散射法,测定了加碱前后聚合物溶液的部分水解聚丙烯酰胺分子线团粒径分布、体相粘度和电导率,考察了NaOH对部分水解聚丙烯酰胺的分子链、水解和溶液离子强度的影响.用界面剪切粘度仪、zeta电位仪和界面张力仪研究了NaOH的加入对部分水解聚丙烯酰胺与煤油之间界面性质的影响.结果表明:随着放置时问的延长,聚合物溶液自身会发生降解;碱使溶液中的离子强度增加,聚合物溶液在碱性环境下水解.碱导致聚合物溶液电导率增加,体相粘度下降,但对聚合物分子链没有明显影响.在界面性质方面,加碱后,聚合物溶液界面张力有所下降,油水界面剪切粘度大幅下降,离子强度和碱性水解的双方面原因导致了Zeta电位负值先增加,再逐渐减小. 相似文献