整体式钒催化剂制备中塑芯材料对热加工性能的影响

整体式钒催化剂是一种新型催化剂,其内部交联通道通过预埋塑芯并煅烧去除的方法制备。塑芯的引入改变了钒催化剂的制备流程,尤其是热加工程序。通过测定钒催化剂热膨胀率、热重、差热和活性等方法,研究了塑料与钒催化剂共烧过程的共热膨胀和失重效应及对钒催化剂性能的影响。结果表明,在煅烧温度段300～400 ℃,煅烧升温速率应控制在15 ℃·h^－1,而塑芯的烧除过程不影响催化剂本身活性。     

堇青石整体式催化剂的研究进展

近年来,堇青石整体式催化剂由于具有低热膨胀性、比表面积大、优良的机械强度和高熔点等特点,在尾气废气处理、化工产品的合成、新能源处理、生化等多个领域得到了广泛应用,并表现出了良好的性能。综述了堇青石整体式催化剂制备的过程及研究进展,并对堇青石整体式催化剂的前景做了展望。     

SnO2表面修饰载体对涂覆式丙烯酸催化剂的影响

采用一步水热法制备了SnO₂表面修饰处理的催化剂载体，并将处理后的载体用于制备涂覆式丙烯酸催化剂。采用X-射线衍射、扫描电镜、氮气吸附的表征方法对载体和催化剂进行了表征。结果发现，经过水热法处理后的载体表面生成了针刺海胆状的SnO₂晶体结构。进一步考察了SnO₂表面修饰对载体和丙烯酸催化剂的性能影响。结果表明，采用针刺海胆结构的SnO₂表面修饰后的载体所制备的钼钒系丙烯酸催化剂的机械强度和选择性均有提高。     

整体式催化剂制备过程中料浆流动特性测定及其对催化剂机械性能的影响

利用浇注压制成型制备了SO_2氧化反应的整体式催化剂,研究了成型过程中不同处理方法和不同的配方对浇注料浆流动性质的影响规律,测定了催化剂料浆在不同处理条件下的塑限、液限、流动度等参数,讨论了浆料流动性质与成型后的催化剂机械强度之间的关系。结果表明通过对催化剂硅藻土载体的酸洗处理、调节催化剂活性组分浆料pH值、对浆料进行捏合处理、适当添加润滑剂等措施,可以有效提高浆料的流动性、降低浆料在相同流动性情况下的含水量,利用该浆料浇注压制成型的催化剂裂纹少、机械强度高。     

钒催化剂生产过程中微波煅烧实验与性能研究

采用微波煅烧法生产钒催化剂 ,并对其性能进行了考察。结果表明 ,与传统方法生产的钒催化剂相比 ,微波煅烧钒催化剂的比表面、机械强度、磨耗等指标均有提高     

氧化铝成型的Pt-SO42-/ZrO2-Al2O3上n-C50/C60的异构化性能

采用浸渍法制备了Pt-SO₄ ^2-/ZrO₂-Al₂O₃（PSZA）催化剂,考察了黏结剂拟薄水铝石的来源对PSZA异构化活性和机械强度的影响,确定了较为适合的黏结剂来源。对氢氧化锆母体制备进行从25g放大10倍至250g,研究放大催化剂的异构化性能。在此基础上考察了Al₂O₃黏结剂含量对PSZA异构化活性和机械强度的影响。采用XRD、TG、XRF等手段对催化剂进行了表征,结果表明：拟薄水铝石的来源不同,结晶度不同,制备的催化剂的异构化活性与机械强度均有差别,拟薄水铝石的结晶度越高,制备的催化剂上的硫含量越低,异构化活性越高,机械强度也越高。此外,放大10倍制备的催化剂异构化性能没有明显变化。黏结剂含量对催化剂的初始异构化活性没有明显影响,而反应稳定性随着黏结剂含量的提高大幅度降低。兼顾催化剂的异构化活性与机械强度,较适宜的Al₂O₃质量分数为5%～10%。     

金属基体整体式催化剂的制备及在VOCs催化燃烧中的应用研究进展

催化燃烧是对挥发性有机物(VOCs)高效率、低污染的处理技术.以金属为基体制备的整体式催化剂因压降低、催化效率高,机械强度和热稳定好等优点是催化燃烧VOCs的研究热点.本文从金属基体结构选择、表面预处理、涂层制备和催化燃烧VOCs几个方面,对近年来金属基体整体式催化剂的研究进行了述评.由此指出,制备高性能的过渡涂层以及...     

云南小石坝硅藻土(高铝)研制钒催化剂初探

一、前言 在钒催化剂的制造中,为开发新的矿土资源,我们初步探讨了云南小石坝硅藻土作为钒催化剂载体的可行性。以云南小石坝硅藻土作载体酶钒催化剂,操作温度宽(370～610℃),起燃温度低(340～360℃),机械强度高[54.9～70.6N/cm(5.6～7.2kgf/cm)](径向酸泡强度),且热稳定性好,适用于工业生产。     

新型纳米V_2O_5催化剂的制备与表征

以片状工业V2O5晶体为原料,采用Sol-gel法制备含纳米V2O5颗粒的溶胶和凝胶,并以此胶体为活性组分、硅藻土为载体制得一种新型纳米钒催化剂,研究了催化剂的显微结构和性能。结果表明,经过酸洗处理后的硅藻土的物理化学性质满足催化剂载体要求,TEM和SEM研究显示,胶体中V2O5颗粒形貌呈现针状或球状,催化剂中的活性组分V2O5颗粒大小仍然处于纳米级别且分散均匀,纳米钒催化剂的强度为61.3N.cm-1,活性达87.4%。     

H2O2/Se改性钒催化剂制备及催化氧化SO2性能研究

提出了一种H₂O₂/Se改性钒催化剂制备的新方法。采用XRF、XRD、SEM、MIP和TG/DSC对催化剂进行表征分析,测定了催化剂催化氧化SO₂转化率,并与国产钒催化剂CHP-75和进口VK-38对比分析。结果表明,H₂O₂/Se改性钒催化剂V@10%H₂O₂-Se/SiO₂具有清晰的表面孔道、较大的孔容、较小的活性组分晶体尺寸和较低熔融相变温度,使其具有较高的催化氧化SO₂活性。该催化剂催化活性高于国产CHP-75,与进口VK-38媲美。高效钒催化剂的设计为国产钒催化剂替代国外进口催化剂提供了一种可能。     

NWS-1型湿法制酸专用钒催化剂的开发研究

针对湿法制酸的工艺特点,通过对钒催化剂载体硅藻土的筛选、精制及钒催化剂配方、制备工艺的改进,研制开发出性能优良的NWS—1型湿法制酸专用钒催化剂。实验室评价和工厂1000h侧流试验结果表明,该钒催化剂具有较高的活性、机械强度和稳定性,能够满足湿法工艺条件下钒催化剂使用性能要求。     

QCS－04耐硫变换催化剂在山西化肥厂工业侧流试验

针对山西化肥厂的特殊工艺条件（粉煤气中焦油、粉煤等成份含量高，催化剂再生频繁，要求催化剂具有高的机械强度），开发出一种具有特殊载体的新型ＣＯ耐流变换催化剂ＱＣＳ－０４，并于１９９５年５月在山西化肥厂第二变换炉进行了侧流试验。结果表明：ＱＣＳ－０４催化剂具有较高的强度、强度稳定性和活性稳定性，并具有容易硫化，活性组份流失率低等特点。     

高效制造球形氨合成催化剂的喷洒成球法

作者发明了一种高效制造球形氨合成催化剂的新方法。研究结果表明,采用固定造粒喷头和旋转造粒喷头直接喷洒成球工艺制造球形氨合成催化剂,具有成球率特别高、球形系数接近1、机械强度高、电耗和成本低、操作安全可靠等特点。     

三叶状钒催化剂的研制

介绍了三叶状钒催化剂的研制。工业宏观活性评价和通气测试表明，三叶状催化剂性能优良，其床层压力降介于圆柱状和环状催化剂之间，为圆柱状催化剂的70％左右。在相同的转化条件下，相对于环状催化剂，三叶状催化剂的装填量可减少16．7％。     

Activity of hydroprocessing catalysts prepared by reprocessing spent catalysts

In this study, two spent catalysts from the 3rd and 4th fixed beds of the atmospheric residue desulfurization (ARDS) process and one spent catalyst from the H-Oil process employing the expanded bed were used as the starting material for preparation of hydroprocessing catalysts. The spent catalysts were used either in a coked or decoked form. The procedures involved pulverizing the spent catalysts before mixing, kneading and extruding with boehmite in the presence of peptizing agent such as HNO₃. The hydrodesufurization (HDS) and hydrodemetallization (HDM) activities of the new catalysts were evaluated in the microreactor using the atmospheric residue derived from Kuwait crude. The new catalysts prepared from the spent catalysts used in the fixed bed reactors exhibited higher activity than that of commercial catalysts. The HDS activity of the new catalysts prepared from spent catalysts used in the ebullated bed reactor was much lower than that of the other catalysts. This was attributed to a high content of vanadium in the former spent catalyst. At the same time, the adverse effect of vanadium on HDM was much less evident.     

Preparation of heavy oil hydrotreating catalyst from spent residue hydroprocessing catalysts

In recent years, increasing emphasis has been placed on recycling spent hydroprocessing catalysts due to environmental regulations which list them as hazardous waste materials. In the present work, the recycling of spent residue hydroprocessing catalysts that contained high levels of vanadium was investigated by using them in the preparation of active new hydrotreating catalyst after subjecting them to different treatments such as decoking, acid-leaching and hydrothermal treatment. Catalyst extrudates containing different levels of V, Mo and Ni on Al₂O₃ were prepared by mixing the spent catalyst powder with boehmite in different proportions followed by peptization, kneading and extrusion. The prepared catalyst extrudates were characterized by chemical analysis and surface area and porosity measurements. The HDS and HDM activities of the catalysts were tested using Kuwait atmospheric residue as feed and compared with that of a reference HDM catalyst. Partial leaching of vanadium from the spent catalyst opened up the pores, and the catalyst prepared by mixing the metal-leached spent catalyst (MLSC) with boehmite had higher surface area and pore volume and showed higher hydrotreating activity than that prepared from unleached spent catalyst. Hydrothermal treatment of the spent catalyst increased its porosity and surface area. Catalysts prepared from hydrothermally treated spent catalyst (HTSC) had higher surface area and pore volume and showed higher HDM and HDS activities than that prepared from the spent catalyst without hydrothermal treatment. The catalysts prepared from the treated spent catalysts also exhibited substantially higher HDM and HDS activities than the reference commercial HDM catalyst. The results indicate that spent catalysts containing high levels of vanadium together with Mo and Ni on Al₂O₃ can be used in the preparation of active HDM/HDS catalysts, and thereby, their environmental problem can be reduced.     

FeO基氨合成催化剂的结构与机械性能研究

通过对氧化态FeO基氨合成催化剂的相组成、晶相结构及铁比值与机械强度的关系的考察研究。结果表明:FeO基催化剂结构紧密,各种粒度的工业催化剂机械磨耗率都较低;机械强度随FeO相的增多而提高,纯FeO相的磨耗率最低;Fe2+∶Fe3+比值在3.47～8.43,机械强度均高于Fe3O4基催化剂,且随Fe2+∶Fe3+比值的上升而增高。为工业生产中保持催化剂的颗粒完整,降低阻力,实现稳产、高产提供了催化剂机械结构性能依据。     

Design of novel Pt-structured catalyst on anodic aluminum support for VOC’s catalytic combustion

Emission control of volatile organic compounds (VOCs) is one of the priorities for environmental catalysis. Catalytic combustion is one of promising technologies for elimination of VOCs. A novel platinum-structured catalyst was designed and is presented in this work. Aluminum was used as support for the catalyst after anodic oxidation treatment and in a shifted arrangement bent, short channels are applied in the design of the structured catalyst. The simulation results show that the novel design of the structured catalyst brings in the higher catalytic activity, compared with the traditional structured catalyst which has long, straight channels. Lastly, the novel structured catalyst was manufactured and its catalytic activity was evaluated with the catalytic combustion of VOC. The results show that the conversion obtained from the reactor with the structured catalyst is almost identical to that obtained from the tube reactor packed with the plate catalyst in which the reaction rate is controlled by surface reactions. Hence, it can be concluded that the mass transfer can be improved by the novel design of the structured catalyst and that the mass transfer in gas phase is not the rate-determining step for the catalytic combustion of VOC.     

Influence of zirconia raw materials on the development of DeNOx monolithic catalysts

Pd-zirconia-based monolithic catalysts were prepared with various commercial zirconia raw materials and a natural magnesium silicate binder, sepiolite, for the selective catalytic reduction (SCR) of NO with CH₄ in oxygen excess. The different textural properties, metastable tetragonal zirconia phase stability, surface acidity, Pd dispersion and catalytic properties of these monoliths were compared to select the most suitable structured catalyst for NO_x control in natural gas-fired power plants. The influence of operating temperature in the two reactions, NO reduction and CH₄ combustion, with the monolithic catalysts was determined. A 0.4 wt.% Pd-zirconia catalyst, manufactured from a sulphated zirconium hydroxide raw material, was selected as the most appropriate in the reaction under study, reaching a maximum NO conversion at 400 °C.