以催化裂化废催化剂粉合成超细 Y 型分子筛

 针对催化裂化 (FCC) 废催化剂细粉带来的环境污染和未开发利用的现状, 以此为原料合成了小晶粒 Y 型分子筛, 并采用 X 射线衍射、扫描电镜、29Si和27Al 固体核磁共振和激光粒度分析等技术对样品进行了表征. 结果表明, 以 FCC 废催化剂细粉为原料可以合成粒径为 200 nm 左右的 Y 型分子筛, 且制备过程中原料的活化方法和导向剂对所得样品结构影响很大. 对原料采用碱熔活化, 并在合成体系中加入导向剂, 所得 Y 型分子筛的相对结晶度提高, 比表面积增大, 粒度减小.     

催化裂化待生剂上有机吸附物种的鉴别分析

为了鉴别分析催化裂化待生剂上分子筛孔道内、外的有机吸附物种，提出了超声萃取提取待生剂上外表面的有机吸附物种方法，优化了萃取条件；对分子筛孔道内的有机吸附物种。采用HF处理待生剂，溶解催化剂分子筛骨架以释放孔内积炭，并用二氯甲烷作溶剂萃取。采用GC-MS分离并鉴别分子筛孔道内、外的有机吸附物种，实验结果显示：在催化剂外表面主要是二环和三环芳烃，而在分子筛孔道内解吸的则是从双环到七元环的多环芳烃。这些结果对研究催化裂化催化剂的性能和结炭的机理提供了重要信息。     

炼油厂催化裂化装置管道气体中氰化物含量的测定

提出了炼油厂催化裂化装置管道气体中氰化物含量的测定方法。优化的采样条件为:在前两个吸收瓶中各装入6mol·L-1氢氧化钠吸收溶液50mL;在第一个吸收瓶中加入碳酸镉;吸收的烟气体积不大于0.1m3;气体流量为2.0~2.5L·min-1。优化的蒸馏条件为:在蒸馏瓶中加入100g·L-1乙二胺四乙酸二钠溶液10mL,在接收瓶内加入40g·L-1氢氧化钠溶液10mL作为吸收液。方法用于吸收后样品的分析,加标回收率在81.7%~92.0%之间。     

Effects of Calcination Temperature on the Acidity and Catalytic Performances of HZSM-5 Zeolite Catalysts for the Catalytic Cracking of n-Butane

The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature.The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.     

Study of Carbon Nanotube Supported Co-Mo Selective Hydrodesulphurization Catalysts for Fluid Catalytic Cracking Gasoline

In this paper, carbon nanotube supported Co-Mo catalysts for selective hydrodesulphurization （HDS） of fluid catalytic cracking （FCC） gasoline were studied, using di-isobutylene, cyclohexene, 1-octene and thiophene as model compounds to simulate FCC gasoline. The results show that the Co-Mo/CNT has very high HDS activity and HDS/hydrogenation selectivity comparing with the Co-Mo/γ-Al2O3 and Co-Mo/AC catalyst systems. The saturation ratio of cyclohexene was lower than 50%, and the saturation ratio of 1,3-di-isobutylene lower than 60% for the Co-Mo/CNT catalysts. Co/Mo atomic ratio was found to be one of the most important key factors in influencing the hydrogenation selectivity and HDS activity, and the most suitable Co/Mo atomic ratio was 0.4. Co/CNT and Mo/CNT mono-metallic catalysts showed lower HDS activity and selectivity than the Co-Mo/CNT bi-metallic catalysts.     

多酸基深度加氢脱硫催化剂的原位表征和反应性能

采用浸渍法合成了镍盐复合的磷钨酸(HPW)/纳米晶HZSM-5固体酸催化剂,其在催化裂化(FCC)汽油加氢改质反应中显示出了良好地深度加氢脱硫活性。 原位电子自旋共振和原位吡啶吸附红外光谱表征手段的研究结果表明,纳米晶HZSM-5沸石上Ni(Ⅱ)结合3电子还原态的HPW(Ⅲ)是FCC汽油深度加氢脱硫反应的活性中心。 探讨了多酸基催化剂在FCC汽油深度加氢脱硫反应中活性改善的原因。     

温度和剂油比对汽油催化裂化脱硫的影响

Increasingly stringent regulations on environmental protection make gasoline desulfurization be a major concern for the present refineries. Accordingly, we proposed an original idea of sulfur reduction by catalytic cracking of FCC gasoline and simultaneously converting most sulfur of sulfides to H 2S. Some progress has been made in exploitation of the catalysts. In this paper, the effect of temperature and catalyst/oil ratio on the FCC gasoline desulfurization over two catalyst samples via catalytic cracking was discussed. The optimum temperature range is 400～420 ℃ for sulfur removal with relatively low cracking loss of gasoline. The highest sulfur removal percentage of 70% can be achieved with a liquid yield of more than 96%. The catalyst samples have higher desulfurization activity and selectivity for the sulfide cracking. In addition, both the gasoline yield and the sulfur content of the desulfurized gasoline decrease with the catalyst/oil ratio.     

Matrix Effects in a Fluid Catalytic Cracking Catalyst Particle: Influence on Structure,Acidity, and Accessibility

Matrix effects in a fluid catalytic cracking (FCC) catalyst have been studied in terms of structure, accessibility, and acidity. An extensive characterization study into the structural and acidic properties of a FCC catalyst, its individual components (i.e., zeolite H-Y, binder (boehmite/silica) and kaolin clay), and two model FCC catalyst samples containing only two components (i.e., zeolite-binder and binder-clay) was performed at relevant conditions. This allowed the drawing of conclusions about the role of each individual component, describing their mutual physicochemical interactions, establishing structure-acidity relationships, and determining matrix effects in FCC catalyst materials. This has been made possible by using a wide variety of characterization techniques, including temperature-programmed desorption of ammonia, infrared spectroscopy in combination with CO as probe molecule, transmission electron microscopy, X-ray diffraction, Ar physisorption, and advanced nuclear magnetic resonance. By doing so it was, for example, revealed that a freshly prepared spray-dried FCC catalyst appears as a physical mixture of its individual components, but under typical riser reactor conditions, the interaction between zeolite H-Y and binder material is significant and mobile aluminum migrates and inserts from the binder into the defects of the zeolite framework, thereby creating additional Brønsted acid sites and restoring the framework structure.     

烯烃裂解中分子筛催化剂的稳定性研究进展

低碳烯烃催化裂解增产丙烯是一项新技术,高水热稳定催化剂的研究和开发是关键技术之一,硅酸铝分子筛催化剂因具有相对较好的稳定性而得到了广泛研究. 本文总结了HY, HZSM-5和 MCM-22等微孔、介孔以及具有微-介孔复合结构的新型分子筛在烯烃催化裂解反应中的稳定性,特别是水热稳定性方面的研究进展,归纳了提高酸性分子筛催化剂水热稳定性的方法,比较了不同方法制得分子筛的催化裂解性能,对高稳定性催化剂在实际应用中的问题和前景进行了探讨,为研发新一代低碳烯烃裂解催化剂提供参考.     

Effects of Temperature and Catalyst to Oil Weight Ratio on the Catalytic Conversion of Heavy Oil to Propylene Using ZSM-5 and USY Catalysts

It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC (fluid catalytic cracking). The effects of temperature and C/O ratio (catalyst to oil weight ratio) on the distribution of the product and the yield of propylene were investigated on a micro reactor unit with two model catalysts, namely ZSM-5/Al2O3 and USY/Al2O3, and Fushun vacuum gas oil (VGO) was used as the feedstock. The conversion of heavy oil over ZSM-5 catalyst can be comparable to that of USY catalyst at high temperature and high C/O ratio. The rate of conversion of heavy oil using the ZSM-5 equilibrium catalyst is lower compared with the USY equilibrium catalyst under the general FCC conditions and this can be attributed to the poor steam ability of the ZSM-5 equilibrium catalyst. The difference in pore topologies of USY and ZSM-5 is the reason why the principal products for the above two catalysts is different, namely gasoline and liquid petroleum gas (LPG), repspectively. So the LPG selectivity, especially the propylene selectivity, may decline if USY is added into the FCC catalyst for maximizing the production of propylene. Increasing the C/O ratio is the most economical method for the increase of LPG yield than the increase of the temperature of the two model catalysts, because the loss of light oil is less in the former case. There is an inverse correlation between HTC (hydrogen transfer coefficient) and the yield of propylene, and restricting the hydrogen transfer reaction is the more important measure in increasing the yield of propylene of the ZSM-5 catalyst. The ethylene yield of ZSM-5/Al2O3 is higher, but the gaseous side products with low value are not enhanced when ZSM-5 catalyst is used. Moreover, for LPG and the end products, dry gas and coke, their ranges of reaction conditions to which their yields are dependent are different, and that of end products is more severe than that of LPG. So it is clear that maximizing LPG and propylene and restricting dry gas and coke can be both achieved via increasing the severity of reaction conditions among the range of reaction conditions which LPG yield is sensitive to.     

利用色谱-反应联合装置研究渣油及其胶质的反应性能

建立一套色谱－反应联合装置，实现了在微量进样条件下对胜利原油减渣中胶质组分的催化裂化反应性能的考察。结果表明，在特殊设计条件下，色谱－反应联合装置具有快速、简便、再现性能良好的特点，可完成对渣油中胶质组分的催化裂化反应性能考察。     

C4/C5烃催化裂解制低碳烯烃的研究进展

从催化剂类型、裂解工艺、催化裂解的影响因素和裂解机理4个方面对国内外C4／C5烃催化裂解制低碳烯烃的研究进行了综述。催化裂解制低碳烯烃催化剂主要采用ZSM-5分子筛系列催化剂，在此基础上发展了酸改性或水热改性高硅ZSM系列分子筛及介孔MCM41分子筛。总结了国内外C4／C5烃的裂解工艺，认为影响催化裂解的主要因素是裂解原料、催化剂类型及工艺条件。目前，裂解机理主要是自由基与碳正离子机理相结合的机理。并简述了本课题组目前有关C4烷烃催化裂解的主要研究进展。     

C4/C5烃催化裂解制低碳烯烃的研究进展

从催化剂类型、裂解工艺、催化裂解的影响因素和裂解机理4个方面对国内外C4/C5烃催化裂解制低碳烯烃的研究进行了综述。催化裂解制低碳烯烃催化剂主要采用ZSM-5分子筛系列催化剂,在此基础上发展了酸改性或水热改性高硅ZSM系列分子筛及介孔MCM-41分子筛。总结了国内外C4/C5烃的裂解工艺,认为影响催化裂解的主要因素是裂解原料、催化剂类型及工艺条件。目前,裂解机理主要是自由基与碳正离子机理相结合的机理。并简述了本课题组目前有关C4烷烃催化裂解的主要研究进展。     

高校危险废弃物管理信息化网络建设的探索

利用先进的网络技术将高校危险废弃物的管理形成有效的闭环,减少化学教学及研究活动对环境的危害,通过对实验室危险废弃物的动态监控,初步掌握各实验室教学及科研工作产生的危险废弃物的情况,从而给出安全环保的合理化建议,促进高校实验室亟待解决的环境保护和安全工作。     

Effect of Hydrogen or Syngas Addition on Light Alkene Production by the Catalytic Oxidative Cracking of Hexane 氢气/合成气添加对正己烷催化氧化裂解制低碳烯烃反应的影响

 采用0.1%Pt/MgAl2O4催化剂研究了H2或合成气的添加对高碳烷烃模型化合物正己烷氧化裂解制低碳烯烃反应的影响. 添加H2实验中,随n(H2)/n(O2)从0增加到3,产物中COx的选择性迅速由22.4%降到4.3%,低碳烯烃的选择性则从61.5%增加到73.8%,正己烷的转化率从62.0%增加到72.8%. 添加合成气对低碳烯烃和CO选择性的影响与添加H2的影响相同,只是添加合成气时正己烷的转化率下降了6%左右. 添加合成气的正己烷氧化裂解过程可提供组成可调的产物(含有低碳烯烃、H2和CO),可不经分离直接用作加氢甲酰化生产低碳烯烃衍生物过程的原料.     

用于NH3选择性催化还原NO的非钒基催化剂研究进展

NH3选择性催化还原NO (NH3-SCR)技术在燃煤电厂烟气脱硝过程中有着多年的工业应用经验,也是最有望实际应用于柴油车尾气NOx催化去除的技术之一.鉴于目前工业化应用的V2O5-WO3 (MoO3)/TiO2催化剂体系应用于柴油车尾气净化仍存在着诸多问题,开发新型、高效、稳定且环境友好的非钒基NH3-SCR催化剂体...     

全二维气相色谱-飞行时间质谱对催化裂化汽油的定性与定量分析

采用全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)对催化裂化汽油全馏分进行了定性与定量分析,建立了相应的分析方法.结果表明,汽油族组成中的烷烃、烯烃、环烷烃、芳烃在全二维点阵谱图中呈分区域、带状的分布特点.GC×GC-TOF MS根据催化裂化汽油组分内分子的沸点及极性差异对其进行两个维度分离,极大地避免了普通色谱法分析过程中沸点相似化合物共流的弊端,实现催化裂化汽油组分的精确分离和准确定性分析.通过引入响应因子,修正了不同性质的烃类在电离源上电离效率的差异,使得TOF对催化裂化汽油族组成的定量结果与普通气相色谱法的定量结果的相关性较好,且应用GC×GC-TOF MS方法获得了催化裂化汽油更为精确的族组成信息.GC×GC-TOF MS为催化裂化汽油精确表征提供了一种有效方法.     

铈基催化剂用于NH3选择性催化还原NOx的研究进展

源自固定源(如燃煤电厂烟气)和移动源(如机动车尾气)排放的氮氧化物(NO_x)造成了严重的大气污染,对其进行减排控制已迫在眉睫. 研究表明, 氨选择性催化还原(NH₃-SCR)技术是消除NO_x的最有效手段之一.铈基催化剂因其良好的氧化还原性能、适当的表面酸性、较高的储/释氧容量以及丰富的资源储备而被广泛用于NH₃-SCR反应. 探讨铈基组分在该反应中发挥的具体作用, 有助于了解相关催化过程的本质, 为现有催化剂的优化和新型催化剂的设计提供科学参考. 基于CeO₂在NH₃-SCR催化剂中扮演的不同角色, 本文从CeO₂作为载体、铈基复合氧化物、表面负载组分(助剂和活性组分)以及特殊结构的铈基催化剂等方面系统地介绍了近年来铈基催化剂在NH₃-SCR反应中的最新研究进展, 并对该领域未来可能的发展方向进行了展望.     

扫帚状氧化铈制备及其对Pt基阳极催化剂催化性能的影响

采用水热合成法,合成了比表面积为175 m²·g^-1,孔径在2~4nm范围内的扫帚状CeO₂。通过微波辅助乙二醇还原氯铂酸法制备了Pt-CeO₂/RGO催化剂,探究扫帚状CeO₂的添加对Pt基催化剂电催化性能的影响。利用X射线衍射仪（XRD）、扫描电镜（SEM）、N₂吸附-脱附、X射线光电子能谱（XPS）对所制备的CeO₂及催化剂进行表征。利用电化学工作站对催化剂进行电化学性能测试。结果表明,催化剂中CeO₂保持原有扫帚状,Pt纳米粒子均匀分布于石墨烯载体表面;当m_RGO∶m_CeO2=1∶2时,添加了扫帚状CeO₂的Pt-CeO₂/RGO催化剂的电催化性能最优,电化学活性表面积为102.83 m²·g^-1,对乙醇氧化的峰值电流密度为757.17 A·g^-1,1 000 s的稳态电流密度为108.17 A·g^-1,对乙醇催化氧化反应的电荷转移电阻最小,活化能最低。     

扫帚状氧化铈制备及其对Pt基阳极催化剂催化性能的影响

采用水热合成法,合成了比表面积为175 m~2·g~(-1),孔径在2~4nm范围内的扫帚状CeO_2。通过微波辅助乙二醇还原氯铂酸法制备了Pt-CeO_2/RGO催化剂,探究扫帚状CeO_2的添加对Pt基催化剂电催化性能的影响。利用X射线衍射仪(XRD)、扫描电镜(SEM)、N_2吸附-脱附、X射线光电子能谱(XPS)对所制备的CeO_2及催化剂进行表征。利用电化学工作站对催化剂进行电化学性能测试。结果表明,催化剂中CeO_2保持原有扫帚状,Pt纳米粒子均匀分布于石墨烯载体表面;当m_(RGO)∶m_(CeO2)=1∶2时,添加了扫帚状CeO_2的Pt-CeO_2/RGO催化剂的电催化性能最优,电化学活性表面积为102.83 m~2·g~(-1),对乙醇氧化的峰值电流密度为757.17A·g~(-1),1 000 s的稳态电流密度为108.17 A·g~(-1),对乙醇催化氧化反应的电荷转移电阻最小,活化能最低。