固体超强酸在催化正己烷异构化反应中失活的研究

研究了固体超强酸催化剂SO4^2-／ZrO2及负载型SO4^2-／ZrO2-SiO2催化剂在催化正己烷异构化反应中的失活与再生问题。结果表明，在催化正己烷异构化反应过程中，催化剂SO4^2-／ZrO2和SO4^2-／ZrO2-SiO2均存在明显的失活现象。失活的主要原因是积炭覆盖了催化剂表面的超强酸中心，但可通过烧炭的方法除去表面的积炭而使催化剂再生。再生后的催化剂的活性并没有明显降低。催化剂SO4^2-／ZrO2-SiO2的催化活性明显低于SO4^2-／ZrO2，催化剂制备过程中焙烧温度有显著的影响。通过对催化剂积炭过程的动力学分析，提出了失活过程的模型，并依此计算了固体超强酸催化烷烃异构化反应的积炭反应的表观活化能。     

Pt/Beta、Pt/SO42-/ZrO2和Pt/WO3/ZrO2催化剂上的正己烷异构化

通过引入K的方法调节Beta分子筛的酸性,考察了K负载量对Beta分子筛酸性的影响。制备了Pt/Beta、Pt/SO42-/ZrO2 与Pt/WO3/ZrO2 3种不同类型的催化剂,考察了它们的正己烷异构化催化活性及酸性与孔道结构对其催化活性的影响。结果表明,催化剂的异构化催化活性与其酸强度和酸量有关,其中酸强度对异构化活的影响更明显。而异构体产物的分布可能与催化剂的孔道结构及正己烷转化率有关,而与催化剂酸性无直接关联。具有合适孔径的催化剂对多支链烷烃的生成更有利,异构化反应可能是受动力学限制的择形反应。     

甲醇乙醇催化合成异丁醛催化剂V2O5的失活研究

研究了在V2O5催化剂上,在常压、反应温度375℃,原料甲醇与乙醇摩尔比为3:1,体积空速为2 h-1条件下一步催化合成异丁醛.考察了催化剂的稳定性和催化剂失活的原因.实验结果表明,反应至330 min后催化荆活性几乎不再变化,此时乙醇转化率在70%左右,而异丁醛的选择性仅为10%左右,催化剂几乎不再具有活性.表征测试结果表明,催化剂失活的原因是:反应过程中结焦;V2O5,在反应过程中被还原为V2O3;V2O5在反应过程结构的变化导致酸量的增加.催化剂失活为可逆失活,高温烧炭再生能使失活催化剂恢复其催化活性.     

SO42-/ZrO2固体超强酸催化剂上异丁烷与丁烯烷基化的研究

在固定床连续性微反活性评价装置上,考察了异丁烷与丁烯在SO24-/ZrO2系列固体超强酸催化剂上烷基化反应的活性和选择性,借助XRD、DTA、NH3-TPD等分析方法对SO42-/ZrO2催化剂的结构和性能进行了表征.结果表明,SO42/ZrO2催化剂表面酸性位的强度与焙烧温度密切相关.同时,Sq2-/ZrO2固体超强酸催化剂上的中强酸位是烷基化反应的主要活性位,但酸强度越高,其比活性越高,而目标产物三甲基戊烷选择性越低.SO42-/ZrO2催化剂的弱酸位有利于烯烃齐聚反应,强酸位有利于裂化反应,氢转移、异构化反应一般发生在中强酸位,与烷基化反应要求的酸性位很接近,烷基化反应酸强度控制在-8.1～-12.7为宜.     

WO3/ZrO2催化烷烃异构化反应研究进展

 介绍了WO3/ZrO2固体超强酸催化剂几种常用的制备方法,概述了制备条件对WO3/ZrO2结构及其对烷烃异构化催化性能的影响,综述了WO3/ZrO2及改性WO3/ZrO2固体超强酸催化剂催化烷烃异构化反应的研究进展。结果表明, WO3/ZrO2固体超强酸对烷烃异构化反应具有较好的催化性能, 催化剂中WO3含量、焙烧温度及ZrO2晶型是影响催化性能的主要因素. 还简要介绍了WO3/ZrO2表面结构, 预测了WO3/ZrO2固体超强酸催化剂今后研究重点。     

Pd-Fe/α-Al_2O_3催化CO偶联制草酸二乙酯催化剂临氢失活研究

一氧化碳常压气相催化偶联制草酸二乙酯的反应中,由于氢的引入致使偶联反应催化剂Pd-Fe/α-Al2O3失活。研究了不同氢含量条件下催化剂失活以及失活催化剂再生规律,发现催化剂的失活为可逆的,且失活速率随原料气中氢含量的增加而加快。应用X射线光电子能谱、程序升温还原等方法对催化剂中Pd的形态变化进行了分析,发现临氢失活催化剂比反应后催化剂的Pd2+含量要低得多。结果表明,原料气中氢的存在抑制了二价钯的烷氧基中间体Pd(OC2H5)2在催化剂上的产生,从而抑制了草酸二乙酯的生成,导致了催化剂的失活。     

固体超强酸催化C5/C6烷烃异构化反应

以石油化工科学研究院新开发的固体超强酸GCS-1为催化刺,考察了反应温度、空速、压力、氢/油摩尔比等因素对C5/C6烷烃异构化反应结果的影响,确定了较为适宜的反应条件.在温度180～190℃,质量空速2.0～3.0 h-1,压力1.4～1.6 MPa,氢/油摩尔比2.0～3.0条件下反应,GCS-1不仅可以表现出较高的异构化催化活性,而且1000 h的寿命试验也证明了该催化剂具有很好的稳定性.与石油化工科学研究院开发的第一代分子筛型异构化催化剂FI-15相比,新一代固体超强酸催化剂GCS-1在反应温度降低70℃、原料空速提高1倍的情况下,C5/C6烷烃异构化率显著提高,异构化产品的辛烷值可以提高2个单位以上,显示出更为优越的异构化催化性能.     

Ni-La/AC甲醇气相羰基化催化剂失活行为的研究

采用等容浸渍法制备了Ni-La/AC双金属催化剂,在连续流动固定床反应装置中,于260℃、1.5 MPa、CO/CH3OH/CH3I摩尔比20/19/17、.5 g-cath.mol-1条件下考察了催化剂的稳定性,并通过BET、XRD、TPR和ICP等技术手段对甲醇气相羰基化反应失活前后Ni-La/AC催化剂进行了表征,考察了催化剂在反应过程中的结构变化和失活行为。结果表明:La组分的引入促进了Ni在催化剂表面的分散,提高了反应的初活性。但是在长时间运转条件下,羰基化活性中心Ni晶粒发生聚集,成为积碳的活性中心,堵塞了部分催化剂微孔,使得催化剂比表面积减小导致催化剂失活。失活催化剂再生后,比表面积有所回升,但Ni晶粒明显增大,反应过程中失活速率加快。此外,活性金属镍的流失以及Ni、La在催化剂上分布的变化也是催化剂失活的原因之一。     

超细负载型Ni-Mo/Al2O3催化剂在渣油加氢裂化中的应用

针对渣油固定床加氢工艺催化剂易结焦失活以及悬浮床加氢工艺催化剂活性偏低的问题,将能悬浮在渣油中的超细负载型催化剂(Ni-Mo/Al2O3)应用于渣油的加氢裂化反应,并在高压釜中考察了反应条件对新疆减压渣油(XJVR)转化率的影响,其中催化剂添加量(质量分数)的考察范围为1%～10%、反应温度为410～450℃、反应时间为0.5～2.5 h、氢气初始压力为5～9 MPa。结果表明,催化剂的添加量对渣油、沥青质以及残炭转化率的影响都很小,但增加催化剂添加量能明显地促进硫的转化,即在此催化体系下,渣油的裂化反应以热反应为主,而加氢脱硫反应则由催化剂的活性中心所决定;反应温度对渣油、残炭、沥青质以及硫的转化率的影响较大,随着反应温度的提高,渣油、残炭、沥青质以及硫的转化率都呈上升的趋势,且前三者的上升趋势更为显著;延长反应时间对反应转化率的影响与提高反应温度所得到的结果类似;当氢气严重过量时,再提高氢气压力对硫转化率没有影响,但可在一定程度上促进残炭和沥青质的加氢反应。     

H2O对Pd/CeO2-TiO2催化剂CO低温氧化反应性能的影响

对比研究了干湿条件下Pd/CeO2-TiO2催化剂的CO低温氧化性能,考察了水存在时催化剂的稳定性和再生性能.结果表明,水的存在对催化剂CO低温氧化活性和稳定性不仅没有负面影响,而且还有一定的促进作用.当空气中含有体积分数为0.5%的CO,0.5%～1.5%的H2O时,在45℃,空速30 L/(h·g)的条件下,氧化态和还原态催化剂均表现出良好的催化稳定性,CO完全转化时间可保持33 h.失活催化剂经过简单的再生过程,其催化活性和稳定性可完全恢复.     

Production of Lubricating Base Oil Using a Moist SiO2/γ-Al2 O3 Catalyst

Abstract

The catalyst SiO₂/γ-Al₂ O₃ treated by micro-wetness air to produce lubricating base oil was studied in this article. The satisfactory reaction temperature, the treatment temperature, and the proper content of active composition was researched. Under the best reaction conditions with a reaction temperature of 170°C, a reaction pressure at 6.0 Mpa, the volume velocity at 0.5 h^?1. The polymerization of α-olefin was performed at a microreactor and produced lubricating base oil with the kinetic viscosity at 38.19 mm² · s^?1, the bromine number at 5.78 g(Br) · (100 g)^?1, and the pour point at ?43.0°C. Then the structure of the catalyst was determined by Brunauer, Emmett and Teller (BET) technology. The result shows that when the optimal micro-wetness air was 45°C, the reaction temperature was 800°C, and the amount of active composition was 12%, and the catalyst has high catalytic activity and wide market prospect.     

Effects of Impregnation Solvents on Catalytic Performance of Co-Ru-ZrO2/γ-Al2O3 Catalyst for Fischer-Tropsch Synthesis

Abstract

Used ZrO₂ modified γ-Al₂O₃ as support, Co-Ru catalysts were prepared by incipient impregnation method. The effects of impregnation solvents on the performances of catalysts were examined. The catalyst was prepared with ethanol solution and high Co dispersion was obtained, exhibiting highest activity of CO hydrogenation, very low methane selectivity, and high heavy hydrocarbon C₅ ⁺ selectivity. The catalysts were prepared with aqueous solution and methanol solution, and the reaction behaviors were similar. The solvent isopropanol caused the lowest catalytic activity and highest methane selectivity. Increasing the reaction temperature enhanced the CO hydrogenation rate, and the CO conversion slightly increased the CO₂ selectivity and favored the formation methane and light hydrocarbons, while the chain growth probability decreased. For the catalyst prepared with ethanol, the CO conversion, the CH₄ selectivity, and the C₅ ⁺ selectivity were 94.16%, 5.65%, and 88.2%, respectively, and the chain growth probability was 0.87 at 493 K, 1.5 MPa, 800 h^?1, and n(H₂):n(CO) = 2.0 in feed.     

H6P2W18O62/MCM-48催化剂的制备、表征及催化绿色合成己二酸

以MCM-48为载体,通过浸渍法制备了H6P2W18O62/MCM-48催化剂,并采用FT-IR、XRD、SEM、EDS对催化剂进行表征。以微波促进30%(质量分数)H2O2氧化环己酮合成己二酸反应为探针,考察了H6P2W18O62/MCM-48的催化性能,并通过正交实验确定了优化的工艺条件。结果表明,采用H6P2W18O62负载量40%的H6P2W18O62/MCM-48催化剂,在优化的合成己二酸的工艺条件下,即催化剂质量分数(以环己酮质量计)5.1%、n(C6H10O)∶n(H2O2)∶n(H2C2O4.2H2O)=100∶450∶1.88、反应温度95℃、微波功率300 W、反应时间3.5h,己二酸收率可达81.3%;催化剂重复使用5次,己二酸收率仍可达到64.6%。     

Hydrogen production by catalytic methane decomposition over Ni,Co, and Ni-Co/Al2O3 catalyst

Hydrogen is a chief source of energy. Catalytic decomposition produces hydrogen and carbon. In this work, x%M/Al₂O₃ (where M is Ni, Co and combined Ni-Co, and x is 10%, 15%, and 30%) has been successfully employed as a catalyst. The effect of activation temperature and active metal type and loading on catalyst perfomance was investigated. The catalysts were characterized with BET, XRD, TPO, TPR, TEM, XPS, and Raman. The results displayed that the 30%Co/Al₂O₃ catalyst activated at 500°C provided the greatest catalytic performance toward methane conversion. 30%Co/Al₂O₃ catalyst activated at 500°C formed amorphous carbon.     

孔径双峰分布γ-Al2O3负载NiMoP催化剂的制备及对蜡油加氢催化性能

在氢氧化铝干胶挤条成型时,调节纳米炭黑的加入量和水/粉质量比,制备了孔径呈双峰分布、具有较大孔容和比表面积的γ-Al2O3载体。当炭黑加入质量分数为13%、水/粉质量比1.15时,制备的孔径呈双峰分布的γ-Al2O3载体的孔容为0.80mL/g、比表面积为309m2/g,4～10nm和10～15nm孔径分别占总孔容50.8%和35.1%(体积分数),采用该载体制备的NiMoP/γ-Al2O3催化剂的孔径呈明显的双峰分布。在反应温度370℃、氢分压10MPa、氢/油体积比700、体积空速1.5h-1的条件下,制备的NiMoP/γ-Al2O3催化剂可使减压和焦化混合蜡油的硫质量分数由25600μg/g降至2070μg/g,脱硫率为91.9%,而参比催化剂仅可使减压和焦化混合蜡油硫质量分数降至3450μg/g,脱硫率为86.5%。     

Characterization of Al2O3–ZrO2 Mixed Oxide Supported Mo Hydrotreating Catalyst

Abstract

A series of molybdenum catalysts supported on Al₂O₃–ZrO₂ mixed oxide containing 50% ZrO₂ and 50% Al₂O₃ were prepared by incipient wetness technique and characterized by BET surface area, X-ray diffraction, temperature programmed reduction and oxygen chemisorption. The catalytic activities for hydrodesulphurization (HDS), hydrogenation (HYD), and hydrocracking (HYC) were determined using thiophene, cyclohexene, and cumene as model compounds, respectively. Results indicate that up to 8 wt% Mo loading, the catalyst is well dispersed and crystallite growth occurred beyond this loading. Also both oxygen uptake and catalytic activities increase with Mo loading up to 8 wt% and then decreases at higher loading. A linear correlation was obtained between oxygen uptake and all catalytic activities and the correlation coefficients obtained suggest that the order of catalytic activities for HDS, HYD, and HYC is: HDS > HYD > HYC. Furthermore, the catalytic activities of the mixed oxide supported catalyst for HDS, HYD, and HYC were higher than those supported on pure alumina and pure zirconia. The incorporation of 3% Co on 8% Mo catalyst was determined to result in enhanced activity for HDS, HYD, and HYC.     

复合SiO2-WO3催化剂的制备、表征及氧化脱除苯并噻吩性能

 采用溶胶-凝胶法制备了SiO₂-WO₃催化剂,并采用XRD、FT-IR、BET、TG-DTA等方法对催化剂进行表征。以苯并噻吩(BT)为模型化合物,H₂O₂为氧化剂,考察了催化剂的活性元素、制备方法、n(W)/n(Si)和焙烧温度对其催化氧化脱硫活性的影响。结果表明,W的引入降低了SiO₂的比表面积,SiO₂-WO₃催化剂中W的主物相为WO₃。在以W为活性组元,且n(W)/n(Si)为0.1时,500℃焙烧得到的SiO₂-0.1WO₃催化剂具有最好的催化脱硫活性。在模拟油20 mL、催化剂SiO₂-0.1WO₃用量0.04 g、n(H₂O₂)/n(S)为15.9、乙腈/模拟油体积比0.3、65℃反应60 min的条件下,苯并噻吩模拟油脱硫率可达99.3%。     

超声波辐照浸渍法制备MnO2/γ-A12O3催化剂及其柴油催化氧化脱硫性能

 分别采用超声波辐照浸渍法和普通浸渍法制备了MnO₂/γ-Al₂O₃催化剂,运用电感耦合等离子体原子发射光谱（ICP-AES）和X射线衍射（XRD）对催化剂进行表征,在空气-异丁醛-MnO₂/γ-Al₂O₃体系中评价其对加氢柴油的氧化脱硫催化性能,并考察了反应温度、异丁醛用量、空气流量、溶剂类型和剂/油体积比对柴油氧化脱硫反应的影响。结果表明,超声波辐照浸渍法制备的MnO₂/γ-Al₂O₃催化剂对柴油氧化脱硫的催化性能明显优于普通浸渍法制备的催化剂。最适宜的催化柴油氧化脱硫反应的条件为：乙腈为溶剂、加氢柴油30 mL、温度35℃、异丁醛20 mmol、空气流量0.06 L/min、超声波辐照浸渍法制备的MnO₂/γ-Al₂O₃催化剂0.08 g、剂/油体积比1/6和催化氧化时间10 min。在此条件下可将柴油硫质量分数从542μg/g 降至31μg/g,柴油脱硫率和回收率分别为94.3%和93.3%。     

Nanocatalysts: Effect of Active-phase and Promoter on Catalytic Properties and Performance in the Hydrodesulfurization Reaction

The influence of various amounts of phosphorus addition on performance of NiMoP/Al₂O₃ and CoMoP/Al₂O₃ nanocatalysts was examined in hydrodesulfurization of thiophene. The nanocatalysts were synthesized via sonochemical technique. The prepared samples were characterized by XRD, FESEM, BET, and FTIR analysis. The catalytic activity in hydrodesulfurization reaction was investigated in a batch stirred slurry reactor at 160°C and atmospheric pressure. The characterizations confirmed highly dispersion of active phase and formation of amorphous AlPO₄ species on the support surface. The results obtained from thiophene hydrodesulfurization showed the nanocatalysts contained 1 wt% of phosphorus had the highest activity. The CoMoP/Al₂O₃ and NiMoP/Al₂O₃ nanocatalysts with optimum phosphorus loading nearly gave 100% conversion of thiophene, so that the sulfur compound concentration in final solution was less than 50 ppm.     

Mathematical modeling of catalytic behavior of catalyst pellets in crude oils after blocking by liquid sulfur

The sulfur recovery unit converts H₂S to elemental sulfur by the Claus process. The process occurs during two combustion and catalytic reactions. Alumina (γ-Al₂O₃) and bauxite (Al₂O₃H₂O) are the main Claus catalysts in crude oils. The volume distribution of micro- and macropores and the parameter of Bethe lattice representing the complex structure of catalyst pellets pores are the most important parameters affecting catalyst performance. This research is aimed at evaluating these parameters impact on effective efficiency of catalyst bed after blocking by liquid sulfur for the second and third reactors. It can be done by considering micro- and macropores as a function of pellet diameter. The results show that pellets with a minimum coordination number or Bethe lattice parameter of 6 are more suitable to use in catalytic reactors. There is a great consistency between the modeling results and the industrial ones. In addition, a catalytic pellet with a diameter of 4.55 mm has the most optimal performance for sulfur recycling processes in industrial crude oil.