压力对USY催化甲苯裂解结焦及其前驱体的影响

研究了压力对USY催化剂催化甲苯裂解结焦及其前驱体的影响。采用热重、红外、13C固体核磁、元素分析、色质联用、程序升温氧化法等手段对催化剂上的焦炭和液相产物中的焦炭前驱体进行了考察。结果表明，沉积在催化剂上的焦炭主要为缩合度较高的多环芳烃，随着压力的升高，总的结焦量减少，液相产物中多环芳烃的环数和质量分数呈增加趋势，证明了超临界流体对焦炭前驱体有萃取效果。并探讨了超临界条件下甲苯催化裂解结焦的机理。     

Effects of CO2 content on the activity and stability of nickel catalyst supported on mesoporous nanocrystalline zirconia

The effects of carbon dioxide content on the catalytic performance and coke formation of nickel catalyst supported on mesoporous nanocrystalline zirconia with high surface area and pure tetragonal crystalline phase were investigated in methane reforming with carbon dioxide. The samples were characterized by XRD, BET, TPR, TPO, TPH, TEM, and SEM techniques. The catalyst prepared showed high surface area and a mesoporous structure with a narrow pore size distribution. The obtained results revealed that the increase in CO2 content increased the methane conversion and stability of the catalyst and significantly reduced the coke deposition. The TPH analysis showed that several species of carbon with different reactivities toward hydrogenation were deposited on the spent catalysts employed under different CO2 contents.     

Mo/HZSM-5催化剂上甲烷无氧芳构化反应中积炭的研究

 对经过程序升温表面甲烷无氧芳构化反应后的Mo／HZSM－5催化剂上的积炭进行程序升温加氢反应和程序升温二氧化碳反应,并对相应的催化剂上的积炭进行程序升温氧化反应和热重实验,以研究催化剂上的不同积炭物种．结果表明,甲烷无氧芳构化反应后有两类烧炭峰,一类是低温烧炭峰,另一类是高温烧炭峰;H2主要对高温烧炭峰发生作用,对低温烧炭峰几乎没有影响;CO2可同时对两种烧炭峰产生影响．由此推论,甲烷在无氧条件下直接转化生成芳烃的反应过程中,沉积在Mo／HZSM－5催化剂上的积炭有三种形式,即：能够与H2反应的积炭,能够与CO2反应的积炭和可能以Mo2C形式存在的物种．     

Synthesis and catalytic performance on methanol conversion of NiAPSO-34 crystals (II): catalytic performance under various reaction conditions

This work has been focused on the catalytic performance for methanol conversion of NiAPSO-34 catalysts which had been synthesized by various preparation methods. The deposited coke during the hydrocarbon transformation was analyzed by temperature-programmed oxidation (TPO) method. For a catalyst with small acid sites and sharp particle size distribution, the catalytic activity and selectivity to ethylene increased compared with other catalysts. It could be confirmed that the catalysts having different acidic densities on external surface and internal surface represented different catalytic activities. Furthermore, it was elucidated that amount of coke formation was strongly related to acidic density on the external crystal surface. On the other hand, catalytic performances under various reaction conditions were exhibited variously and the deposited coke amount was also various. In particular, a surprising result was that the catalytic performance was not changed on the revived catalyst by thermal treatment at 600°C for 3 h.     

甲烷无氧芳构化反应中Co助剂对Mo／HZSM-5

 甲烷在Co－Mo／HZSM－5催化剂上进行无氧芳构化反应的评价结果表明，Co的添加大大提高了Mo／HZSM－5催化剂在反应过程中的稳定性．BET实验证明，反应后的积炭对Co－Mo／HZSM－5催化剂孔道堵塞的程度较小．对积炭催化剂进行的一系列程序升温表面反应（如TPH，TPCO2和TPO）结果表明，TPO谱上有两个峰温明显不同的烧炭峰，Co的添加明显抑制了高温积炭的生成．H2主要与高温积炭发生反应，这部分积炭是催化剂失活的主要原因；CO2对低温积炭的影响则尤为明显．TEM结果表明，积炭催化剂上存在丝状积炭物种．碳丝不能与H2反应，但能被CO2除去．Co的添加促进了丝状积炭物种的生成，碳丝并不是导致催化剂失活的因素．     

Dry reforming reaction over nickel catalysts supported on nanocrystalline calcium aluminates with different CaO/Al2O3 ratios

Nanocrystalline calcium aluminates with different CaO/Al2O3 ratios were prepared by a facile co-precipitation method using Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG, MW: 5800) as a surfactant. They were employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by X-ray diffraction (XRD), N2 adsorption (BET), temperature-programmed reduction and oxidation (TPR-TPO), and scanning electron microscopy (SEM) techniques. Catalysts showed a relatively high catalytic activity and stability. TPR analysis revealed that the catalysts with higher CaO content are more difficult to be reduced. TPO analysis showed that the 5 wt%Ni/CA and 5 wt%Ni/C12A7 catalysts with higher CaO amount were effective against coke deposition.     

CH4 reforming with CO2 for syngas production over La2O3 promoted Ni catalysts supported on mesoporous nanostructured γ-Al2O3

Nanostructured γ-Al₂O₃ with high surface area and mesoporous structure was synthesized by sol-gel method and employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by XRD, N₂ adsorption-desorption, TPR, TPO, TPH, NH₃-TPD and SEM techniques. The BET analysis showed a high surface area of 204 m²·g⁻¹ and a narrow pore-size distribution centered at a diameter of 5.5 nm for catalyst support. The BET results revealed that addition of lanthanum oxide to aluminum oxide decreased the specific surface area. In addition, TPR results showed that addition of lanthanum oxide increased the reducibility of nickel catalyst. The catalytic evaluation results showed an increase in methane conversion with increasing lanthanum oxide to 3 mol% and further increase in lanthanum content decreased the catalytic activity. TPO analysis revealed that the coke deposition decreased with increasing lanthanum oxide to 3 mol%. SEM and TPH analyses confirmed the formation of whisker type carbon over the spent catalysts. Addition of steam and O₂ to dry reforming feed increased the methane conversion and led to carbon free operation in combined processes.     

流化床甲烷/丙烷临氧CO2重整制合成气反应研究

研究了流化床反应器中甲烷、丙烷临氧自热CO2重整制合成气反应中不同催化剂的性能及表面积碳行为，并用热重分析、激光拉曼及透射电镜研究了催化剂表面的积碳物种及积碳量。结果表明，贵金属Pd、Pt由于对烷烃有较强的裂解作用，镍基及贵金属修饰的镍基催化剂表面有大量的纤维状炭生成；碱土和稀土金属改性的镍基催化剂有较好的抗积碳性能，大量碱土金属CaO修饰微球硅胶后负载的镍基催化剂在同等的反应条件下没有发现积碳，碱土金属对催化剂表面碱性的增强是催化剂抗积碳性能提高的原因。     

CO2 reforming of methane over nickel catalysts supported on nanocrystalline MgAl2O4 with high surface area

In this paper dry reforming of methane (DRM) was carried out over nanocrystalline MgAl2O4-supported Ni catalysts with various Ni loadings. Nanocrystalline MgAl2O4 spinel with high specific surface area was synthesized by a co-precipitation method with the addition of pluronic P123 triblock copolymer as surfactant, and employed as catalyst support. The prepared samples were characterized by X-ray diffraction (XRD), N2 adsorption, H2 chemisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), temperature- programmed desorption (TPD) and transmission and scanning electron microscopies (TEM, SEM) techniques. The obtained results showed that the catalyst support has a nanocrystalline structure (crystal size: about 5 nm) with a high specific surface area (175 m2 g-1) and a mesoporous structure. Increasing in nickel content decreased the specific surface area and nickel dispersion. The prepared catalysts showed high catalytic activity and stability during the reaction. SEM analysis revealed that whisker type carbon deposited over the spent catalysts and increasing in nickel loading increased the amount of deposited carbon. The nickel catalyst with 7 wt% of nickel showed the highest catalytic activity.     

Characterization of the Effects of Vanadium Traps in Cracking Catalysts by Imaging Secondary Ion Mass Spectrometry and Microactivity Test

The vanadium trapping effect of Mg and La containing additives in cracking catalyst contaminated with 2300 ppm Ni and 4700 ppm V has been analyzed by microactivity test (MAT) and imaging secondary ion mass spectrometry (SIMS). The results of SIMS imaging are consistent with cracking activity data and show that the La/spinel is a superior vanadium trap for the fluid catalytic cracking of hydrocarbons (FCC) operation. La/spinel serves as a dual function additive for both vanadium trap and SO_x removal. The optimum amount of La/spinel added to the cracking catalyst is about 15% by weight. This results in an increased catalytic activity, an increase in gasoline yield, and a decrease in coke and gas factors. The MgAl₂O₄ phase of Mg/Al₂O₃ additive is found capable of trapping vanadium while its MgO of Mg/Al₂O₃ phase can migrate to zeolite particles (the active component of the FCC catalyst) that, in turn, causes a decline in the activity of that catalyst.     

供氢剂与分散型催化剂协同作用的研究

以辽河渣油为原料,四氢萘为供氢剂,二烷基二硫代氨基甲酸钼为油溶性催化剂在高压釜中进行裂化反应,比较了临氢裂化,临氢供氢裂化,催化加氢裂化以及供氢剂与分散型催化剂共同存在下的加氢裂化,在同样生焦量的情况下,渣油裂化转化率的顺序为：临氢催化供氢过程＞临氢催化过程＞临氢供氢过程＞临氢过程,同时发现供氢剂与分散型催化剂在渣油加氢裂化过程中具有协同作用,与单独使用分散型催化剂的改质反应相比,供氢剂的协同作用不但可以在低转化率下延迟生焦诱导期,提高渣油生焦前的最大转化率,而且在高转化率下对渣油的缩合反应有更大的抑制作用。由420－440℃四集总表观动力学模型计算出的动力学速率常数和活化能表明,供氢剂与分散型催化剂产生的协同作用提高了沥青质和焦生成的活化能,极大地抑制了沥青质和焦生成 速率,而对可溶质生成馏分油的裂化反应的抑制作用很小。     

氧化镁负载的钼钒磷酸铜催化剂的积碳行为

研究了氧化镁负载的钼钒磷酸铜催化剂在正己醇氧化反应中的积碳行为. 结果表明, 积碳主要以CHx形式存在于催化剂表面, 积碳的形成没有导致催化剂的失活. XRD, IR和XPS等光谱表征结果说明积碳后催化剂结构没有发生改变, 并且载体表面的钼钒磷酸铜有利于积碳的消除. TPO研究结果表明, 积碳在催化剂上有两种存在位置: 一种沉积在钼钒磷酸铜表面, 这种位置的积碳在低温下容易被烧除; 另一种沉积在载体氧化镁的表面, 需要高温才能烧除. 随着反应时间的增加, 积碳量达到定值.     

Research on Hazardous Waste Removal Management: Identification of the Hazardous Characteristics of Fluid Catalytic Cracking Spent Catalysts

Fluid catalytic cracking (FCC) spent catalysts are the most common catalysts produced by the petroleum refining industry in China. The National Hazardous Waste List (2016 edition) lists FCC spent catalysts as hazardous waste, but this listing is very controversial in the petroleum refining industry. This study collects samples of waste catalysts from seven domestic catalytic cracking units without antimony-based passivation agents and identifies their hazardous characteristics. FCC spent catalysts do not have the characteristics of flammability, corrosiveness, reactivity, or infectivity. Based on our analysis of the components and production process of the FCC spent catalysts, we focused on the hazardous characteristic of toxicity. Our results show that the leaching toxicity of the heavy metal pollutants nickel, copper, lead, and zinc in the FCC spent catalyst samples did not exceed the hazardous waste identification standards. Assuming that the standards for antimony and vanadium leachate are 100 times higher than that of the surface water and groundwater environmental quality standards, the leaching concentration of antimony and vanadium in the FCC spent catalyst of the G set of installations exceeds the standard, which may affect the environmental quality of surface water or groundwater. The quantities of toxic substances in all spent FCC catalysts, except those from G2, does not exceed the standard. The acute toxicity of FCC spent catalysts in all installations does not exceed the standard. Therefore, we exclude “waste catalysts from catalytic cracking units without antimony-based passivating agent passivation nickel agent” from the “National Hazardous Waste List.”     

DEHYDROGENATION AND AROMATIZATION OF METHANE IN THE ABSENCE OF OXYGEN OVER DOPED Mo/HZSM-5 CATALYSTS

研究了在Ｍｏ／ＨＺＳＭ－５催化剂上添加助剂以及不同的反应预处理温度对甲烷无氧脱氢芳构化反应的影响。实验结果表明，由于第二组分的添加，Ｍｏ／ＨＺＳＭ－５催化剂的活性和选择性都得到了较大程度的改善。预处理温度是影响催化剂反应性能的关键因素。Ｍｏ－Ｒｕ／ＨＺＳＭ－５催化剂经过８７３Ｋ空气预处理后，甲烷在９７３Ｋ的转化率约为１０％，催化剂的稳定性也得到较大程度的提高。ＴＰＳＲ实验结果表明，Ｒｕ的加入降低了芳烃生成的温度。ＴＰＯ和ＤＴＡ实验结果表明，在Ｍｏ－Ｒｕ／ＨＺＳＭ－５催化剂上可生成较多的碳物种，结合反应结果，可以认为反应过程中生成的碳物种对甲烷的无氧脱氢芳构化反应是起积极作用的     

碱氮化合物喹啉催化裂化转化规律的研究

采用固定床微反活性实验装置，以甲苯、十六烷、四氢萘为溶剂，研究了碱性含氮化合物喹啉的催化裂化转化规律。反应温度、催化剂与原料油的质量比、空速、原料氮含量都影响待生催化剂的氮含量和氮在产物中的分布。催化剂的酸性、烃类溶剂的供氢能力对喹啉裂化有显著影响。催化裂化待生催化剂上的焦炭由烃生焦、吸附氮焦和缩合氮焦组成。提出了喹啉催化裂化的可能转化途径：喹啉通过物理或化学作用吸附于催化剂表面，或在催化剂上脱氢缩合生焦；喹啉烷基化；喹啉加氢生成四氢喹啉，四氢喹啉进一步裂化转化为吡啶、苯胺和氨。     

Co/Al2O3催化剂上积炭的研究

甲烷的二氧化碳重整制合成气是近年来甲烷催化转化的一个重要方面,而所用催化剂的积炭问题仍是影响催化剂活性和寿命的主要因素之一．近年来,对催化剂表面的积炭形式有一些报道［１］,但对积炭的种类及其与催化剂活性的关系很少有报道．本文从经低温焙烧的Ｃｏ／Ａｌ２...     

不同条件下苯与丙烯烷基化反应的催化剂失活研究

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。     

Hydrogen Effect on Coke Removal and Catalytic Performance in Pre-Carburization and Methane Dehydro-Aromatization Reaction on Mo/HZSM-5

1. Introduction As an effective utilization of methane, the methane dehydro-aromatization was focused in the last decade [1-28]. Over the Mo/HZSM-5 bi- functional catalyst at high reaction temperature, methane can be converted into light aromatics (ben- zene and naphthalene) and hydrogen. Mo active species can activate the C—H bond of methane; and HZSM-5 supplies the acid sites for the oligomeriza- tion and cyclization of hydrocarbons to form aromat- ics, and suppresses the deeper condens…     

结焦催化剂上焦炭氢碳比的测定方法

提出了一种测定裂化结焦催化剂上焦碳H/C的方法--酸溶-元素分析法。该方法主要利用HF和HCl将焦碳从催化剂上进行剥离，然后利用元素分析仪测定焦碳中的碳含量和氢含量，从而可以得到结焦催化剂上焦碳的H/C质量比。这种测定方法避免了在测氢过程中催化剂结晶水和吸附水对测定结果的影响，大大提高了催化剂上焦碳H/C的测定精度。     

预处理气氛对Co-ZrO2共沉淀催化剂结构的影响

考察了共沉淀Co-ZrO2催化剂在不同气氛(Ar、H2、CO和CO+H2)、不同温度下处理后, 催化剂织构、晶相以及形貌的变化规律. 结果表明, 在惰性气氛或氢气氛处理过程中, 催化剂在500 ℃以上发生明显烧结. 经上述处理并暴露于空气后, 催化剂中钴物种均以Co3O4形式存在, 且催化剂粒子外形无明显变化. CO气氛还原使催化剂破碎严重, 同时发生明显的积碳现象, 催化剂中钴物种以面心单质钴为主要形式. 合成气处理对催化剂破坏行为不明显, 但催化剂烧结现象严重, 催化剂中Co物种以面心立方和六方两种晶型共存.