FCC催化剂的镍中毒

本文总结了关于流化催化裂化（FCC）催化剂上镍沉积方式、形态和镍沉积对催化裂化反应影响的研究成果。分析了镍中毒引起催化剂失活的原因,对当前FCC加工过程中防止镍中毒的方法进行了总结和比较,并对今后国内FCC催化剂镍中毒研究课题提出建议。     

催化裂化金属钝化剂研究进展

重油中钒(V)、镍(Ni)在FCC过程中会沉积在催化剂上,导致催化剂失活。金属钝化剂是降低钒、镍对FCC催化剂污染的有效方法。主要分为单一和复合多功能两大类。文中介绍了重金属钒、镍对催化剂污染机理,综述了各种钝化剂研究进展及工业应用状况,为我们开发新型金属钝化剂奠定一定基础,指出无毒、高效、水溶性复合多功能金属钝化剂是今后的主要发展方向。     

流化床催化裂化钒钝化工艺

<正> Nalco化学公司介绍了一种对流化床催化裂化钝化钒中毒的新工艺。当裂化含有钒杂质的重质烃类原料时,此工艺可延长FCC(流化床催化裂化)催化剂寿命。增加FCC的产率,降低FCC催化剂的消耗量。此新工艺使用了某种锡添加剂,可以降低钒沉积在FCC催化剂上的钝化和脱氢效应。当适量使用锡添加剂时,能降低钒在氢     

镧铈比对FCC催化剂性能的影响

用不同镧铈比改性由原位晶化合成的Y型分子筛,探索了其在离子交换和焙烧过程中的影响.利用XRD、微反活性评价、固定流化床反应性能评价等测试手段对催化剂样品进行了表征,研究了其对FCC催化剂反应活性、产品分布、选择性和抗镍钒污染性能的影响.结果表明:镧铈改性有利于提高Y型分子筛结构的稳定性,其中低稀土时,镧铈比为0∶1的作用更明显;而高温或水蒸气氛围焙烧时,镧铈比为1∶1和1∶0的作用更明显;经镧铈比为1∶1和1∶0改性的FCC催化剂转化率和液体产品收率较高,而经镧铈比为0∶1改性的FCC催化剂汽油和重油收率较高.不同镧铈比改性的FCC催化剂在抗镍钒重金属污染实验中都能保留较高的微反活性,其中镧铈比为1∶0的FCC催化剂抗镍钒重金属污染性能最好.     

催化裂化金属钝化剂研究进展

FCC 过程中, 沉积在沸石催化剂上的金属镍和钒会导致催化剂严重失活, 加入金属钝化剂是解决上述问题的经济有效的办法。本文综述了沸石催化剂上镍和钒的污染及其钝化机理,以及金属钝化剂的研究进展, 指出研制无毒、高效的钝镍剂、钝钒剂以及钝镍钝钒双功能钝化剂是今后发展的主要方向。     

钒对催化裂化催化剂活性的影响

随着石油加工技术的拓展，二次加工原料使用越来越广泛，但同时带来了重金属对催化裂化催化剂中毒问题。镍对催化裂化催化剂的中毒作用已被国内认识，但钒对催化裂化催化剂的中毒影响尚未引起人们重视。     

钒对FCC催化剂脱除噻吩类硫化物性能的影响

催化裂化过程(FCC)中使用催化剂脱硫对生产清洁燃料具有重要意义。文中通过文献调研,阐述了噻吩类硫化物在FCC催化剂上的裂化依赖于B酸和L酸的协同作用原理,指出以L酸碱对化合物修饰FCC催化剂可改善其表面的弱L酸分布,增强催化剂对噻吩类硫化物的选择性吸附能力,提高FCC催化剂脱除噻吩类硫化物性能。氧化钒作为典型的L酸碱对化合物,利用其修饰FCC催化剂可改善裂化催化剂的脱硫活性。鉴于氧化钒对FCC催化剂的活性组分分子筛存在一定的破坏作用,FCC催化剂的载体是较适宜的修饰位置。低价态钒较高价态钒对噻吩有着更强的化学吸附能力,因而采用还原预处理后的催化剂可得到较好的脱硫效果。     

废FCC催化剂在LPG吸附脱硫中的资源化利用

金属污染是导致流化催化裂化（FCC）催化剂失活的重要因素,充分利用沉积的重金属是废FCC催化剂资源化的关键。本文将废FCC催化剂引入到轻质油品吸附脱硫领域,以脱除液化石油气（LPG）中的二甲基二硫醚作为考核目标,验证了废FCC催化剂作为脱硫剂的可行性。除去废FCC催化剂表面积炭后,其脱硫性能得到明显改善,在常温、质量空速为4.0h^-1的条件下,LPG中硫化物质量分数从382mg/m³脱除至40mg/m³。镧、铁、镍、钒、钙、锑6种金属在新鲜催化剂和焙烧后废催化剂上的总质量分数从10.2%升高至46.6%,6种金属按照对应含量分别固载在新鲜催化剂上,脱硫效果较未改性新鲜催化剂均有明显提升。验证实验表明,导致FCC催化剂失活的金属具有较高脱硫活性,废FCC催化剂作为轻质油品脱硫剂具备工业前景。     

钒钛基SCR脱硝催化剂碱土金属中毒

分别制备了钒钨体系和钒钼体系的新鲜催化剂,并通过浸渍法、固态扩散法与干混法分别制备了碱土金属中毒的催化剂,比较了中毒方法、碱土金属以及催化助剂种类等因素对催化剂脱硝活性的影响,并利用程序升温脱附（NH₃-TPD）、程序升温还原（H₂-TPR）和X射线光电子能谱分析（XPS）等表征手段进行分析。结果表明,3种中毒方法中,浸渍法碱土金属中毒对催化剂毒害作用最大;Ca对催化剂的毒性大于Mg,且钒钼体系催化剂比钒钨体系催化剂具有更强的抗碱土金属中毒性能。碱土金属的存在会降低催化剂表面的总酸量与酸位点的强度,提高催化剂的还原温度,改变活性组分的价态并降低催化剂上表面活性氧的比例。     

具有抗镍性能的FCC催化剂基质

用两种不同比表面积和孔径分布的氧化铝作为基质添加组分制备催化剂，考察不同基质对FCC催化剂性能的影响。结果表明，添加大孔径、低比表面的氧化铝可改善FCC催化剂的重油转化能力、焦炭选择性以及抗镍性能。     

从钒渣中提取钒的新方法

提出了从废催化剂中分离镍、铝后得到的钒渣中回收钒的方法,重点分析了电解分离法的可行性.     

Effect of metal—organic compounds on thiophene hydrodesulphurization over sulphided Co(Ni)Mo/Al2O3 catalysts

Deactivation effects in hydrodesulphurization of thiophene in a pulse reactor over cobalt and nickel promoted Mo/Al₂O₃ catalysts and with vanadium and nickel naphthenate additions were studied. The catalysts were sulphided with CS₂ in hydrogen, and an initial reduction in hydrogen was found to be unnecessary. In the hydrodesulphurization of thiophene smaller changes are observed. A fast initial coking effect is indicated. After regeneration, strongly bonded sulphate species are obtained. Deactivation by the addition of nickel or vanadium naphthenate in a low concentration works similarly. At higher doses, vanadium naphthenate affects both catalysts more strongly than nickel naphthenate. X-ray photoelectron spectroscopy indicates that the metal compounds deposit to a higher extent at the catalyst particles' exterior than at interior surfaces at high levels of additions.     

催化裂化金属钝化剂的研究

催化裂化过程中沉积在催化剂上的重金属会导致催化剂严重失活,文中叙述了重金属污染危害及减少污染的几种方法。在研究有害金属对催化裂化催化剂污染机理的基础上,分析了钝化剂的作用、钝化机理以及在优化催化剂的使用环境,改善产品分布等方面所起到的积极作用。阐述了重油催化裂化金属钝化剂(钝钒剂、钝镍剂)今后的发展方向。     

加氢处理温度对渣油中杂质脱除率的影响

利用渣油加氢中试装置,考察了原料渣油在不同反应温度下经级配催化剂加氢处理前后渣油性质的变化,揭示了硫、氮、镍、钒和残炭的脱除分布规律。结果表明,在恒定温度下,随催化剂活性增加,加氢处理渣油中硫、氮、镍、钒和残炭的含量降低;随反应温度升高,同一反应器得到的渣油杂质含量降低。硫、氮、镍、钒和残炭的总脱除率随反应温度增加而增加,但杂质在各反应器中的脱除率分布不同,50％的镍和60％的钒在前两个反应器中脱除,硫主要在R3和R4反应器中脱除,氮主要在R4和凡反应器中脱除,而残炭则在R5、R4和R5反应器中脱除,随温度变化杂质的脱除率分布呈现各自的变化趋势。     

Study of accelerated deactivation of hydrotreating catalysts by vanadium impregnation method

The main causes of catalysts deactivation for hydrotreating are coking and metals deposition. In this present work, accelerated deactivation of hydrotreating catalysts was studied. In this respect, vanadium which is deposited with nickel during hydrotreating reaction was impregnated into the fresh hydrotreating catalyst. Different percentage of vanadium was impregnated and their hydrodemetalization (HDM) and hydrodesulfurization (HDS) activities were studied in bench-scale reactor of heavy crude oil. Accelerated deactivations for both HDM and HDS were observed on vanadium impregnated catalysts. The rate of HDS deactivation was faster than that of HDM reaction. The rapid deactivation of HDS may be due to the coverage of active sites by impregnated vanadium atom. The deactivation is slower when the V loading is low; but above 10 wt% loading a rapid deactivation is observed. A comparison of deactivation is made in between normal deactivation and the deactivation by vanadium impregnation. It was found that deactivation by vanadium impregnation is lower than that of normal deactivation. It suggests that at initial stage the formation of coke causes deactivation of the catalyst whereas at later stage when metals sulfides deposition is quite high, these sulfides take part in deactivation.     

催化裂化催化剂抗重金属技术应用与进展

简述催化裂化原料油中镍、钒、铁、钙、钠等重金属对催化裂化催化剂选择性和活性的影响,介绍抗镍、抗钒、抗铁和其他重金属技术的应用和进展,为新型抗重金属催化裂化催化剂的研究和发展提供思路。     

Influence of NH3 and NO oxidation on the SCR reaction mechanism on copper/nickel and vanadium oxide catalysts supported on alumina and titania

The influence of ammonia and nitric oxide oxidation on the selective catalytic reduction (SCR) of NO by ammonia with copper/nickel and vanadium oxide catalysts, supported on titania or alumina have been investigated, paying special attention to N₂O formation. In the SCR reaction, the VTi catalyst had a higher activity than VAl at low temperatures, while the CuNiAl catalyst had a higher activity than CuNiTi. A linear relationship between the reaction rate of ammonia oxidation and the initial reduction temperature of the catalysts obtained by H₂-TPR showed that the formation rate of NH species in copper/nickel catalysts would be higher than in vanadia catalysts. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) showed that copper/nickel catalysts presented ammonia coordinated on Lewis acid sites, whereas ammonium ion adsorbed on Brønsted acid sites dominated on vanadia catalysts. The NO oxidation experiments revealed that copper/nickel catalysts had an increase of the NO₂ and N₂O concentrations with the temperature. NO could be adsorbed on copper/nickel catalysts and the NO₂ intermediate species could play an important role in the reaction mechanism. It was suggested that the presence of adsorbed NO₂ species could be related to the N₂O formation.     

Vanadium interactions with treated silica aluminas

Poisoning of fluid cracking catalysts by vanadium, nickel, iron and copper can decrease the selectivity and overall activity of such catalysts. Silica alumina is often used as a matrix to disperse the active zeolite component, to crack large hydrocarbons at initial stages of reaction and for stability of the fluid cracking catalyst. Vanadium poisons are particularly bothersome due to zeolite destruction by vanadium. This paper explores the interaction of vanadium with various silica aluminas including those with rare earth and magnesia contents. The effects of calcination and steaming were also determined. Spectroscopic techniques such as luminescence, diffuse reflectance, electron paramagnetic resonance, X-ray photoelectron spectroscopy and secondary ion mass spectrometry methods were used to study the oxidation state, chemical composition, and number and type of vanadium species in these materials. The results show that vanadium moves into the particle interior when magnesium or rare earth oxides are present. This is responsible for the decreased mobility of vanadium even during steaming conditions and results in higher catalytic selectivity for catalysts containing these materials.     

重油催化裂化装置抗重金属镍污染的措施

重金属镍和钒在催化裂化催化剂上的沉积会导致催化剂的失活和选择性下降。大港油田炼油厂针对催化原料中重金属镍含量高的实际情况,采取了使用金属钝化剂、干气预提升、定期卸出部分平衡剂并补充新鲜剂、选用抗镍能力强的催化剂等一系列钝镍措施,取得了较好的工业应用效果。     

FCC金属钝化剂的制备研究进展

从制备方法、使用性能以及理化性质3个方面综合论述了国内外金属钝化剂研究的进展情况,重点讨论了金属钝化剂的制备方法,金属钝化剂可以抑制镍和钒等金属对催化裂化催化剂的污染,使被污染催化剂的性质得到改善,水溶性金属钝化剂比油溶性金属钝化剂具有更多的优点,采用非锑基金属钝化剂代替有毒的锑基金属钝化剂将是未来的发展方向。