Influence of Al2O3 and TiO2 supports on catalytic performance of Ni and Co catalysts for gasification of glycerol waste

Since the constant increase in petroleum price, use of glycerol waste, which is a byproduct from biodiesel production, as a partial replacement for fossil fuels via thermochemical conversion waste to energy processes is more practical. Gasification reaction has attracted a lot of interest by producing syngas rich in CO and H2. This syngas can be converted to clean liquid fuels, such as methanol and Fischer-Tropsch oil. Nickel and Cobalt catalyst was widely used in steam reforming reaction. ethanol etc. The aim of this work is to prepare and characterize 5.0 and 10.0%wt of Ni and Co catalysts using the impregnation method on various supporters, such as alumina and titanium oxide （TiO2） and to evaluate their catalytic performance. The specific surface area of developed catalysts was measured. X-ray diffraction （XRD） was applied to determine phase and crystallized size of the catalysts. Examination of the morphology. elemental composition and distribution of metal on the catalysts support were carried out using scanning electron microscopy （SEMi and energy dispersion spectroscopy （EDS） and x-ray mapping. The catalytic performance of prepared catalysts was test at 700 and 900℃ temperature of reaction. 1.87% O2. The result showed that the synthesized nickel and cobalt catalysts via impregnation method using Al2O3 and TiO2 as the catalyst support were suitable for glycerol conversion.     

Study on Deactivation and Cracking Performance of Catalysts Containing Y and MFI Zeolites

This article investigated the deactivation caused by hydrothermal treatment and metal contamination of two cracking catalysts containing the Y and ZRP-1 zeolites aimed at maximization of light olefin yield. Test results had shown that the hydrothermal stability and resistance to metal contamination of the ZRP-1 zeolite were apparently better than those of the Y zeolite. Hydrothermal treatment and metal contamination had not only changed the catalytic cracking performance of respective zeolites, but at the same time had also modified to a definite degree of the relative proportions of effective components in these two zeolites and affected the synergistic effects between them, resulting in a relative enhancement of secondary cracking ability of the catalyst and increased olefin selectivity in the FCC products. In the course of application of catalyst for maximization of light olefins yield appropriate adjustment of the relative proportion of two active components can help to alleviate the products distribution and selectivity changes caused by deactivation of FCC catalysts.     

Hydrodeoxygenation of Phenol on Beta Zeolite Catalysts

Biomass is considered the largest renewable energy source and an important alternative for biofuel production. The fast pyrolysis of biomass is an economical and advantageous to get bio-oil. However, bio-oil has a large amount of oxygenated compounds and needs upgrade. The catalytic process of HDO （hydrodeoxygenation） is the most efficient way to remove oxygen from the bio-oil. In this paper, it was studied the HDO phenol （300 ℃ and 35 atm） on catalysts based on cobalt or copper oxides supported on HBeta zeolite. The catalysts were characterized by XRD （X-ray diffraction）, FTIR （infrared spectroscopy） and NH3-TPD （desorption of ammonia）. The results showed the presence of CO304 （cobalt oxide） and CuO （copper oxide）. The measurements showed the presence of acid sites weak, moderate and strong and that the impregnation of the metal oxide modifying the acidity of the support. The results showed the following order HDO conversion： CoHBeta 〉 CuHBeta 〉 HBeta. The presence of the cobalt or copper catalysts contributes to the increase in conversion due to hydrogenation. All catalysts were selective to benzene, but only the impregnated catalysts showed selectivity to cyclohexane and cyclohexene.     

镓对PtSnNa/ZSM-5催化剂丙烷脱氢反应性能的影响

PtSnNaGa/ZSM-5 catalysts with different contents of Ga were prepared and characterized by X-ray diffraction (XRD), nitrogen adsorption, hydrogen chemisorption, ammonia temperature-programmed desorption (NH3-TPD), hydrogen temperature-programmed reduction (H2-TPR), and temperature-programmed oxidation (TPO) techniques. The performances of these catalysts for propane dehydrogenation were investigated. The test results indicated that the addition of Ga not only could improve the catalytic stability and propene selectivity, but also could effectively prevent the catalysts from coking. It was found that the PtSnNaGa(0.5 m%)/ZSM-5 catalyst exhibited the best performance in terms of propene selectivity and propane conversion. The high catalytic performance was most probably attributed to the presence of Ga that could strength- en the interaction between metals and the support to stabilize the catalytic active sites.     

Preparation of hierarchical ZSM-5 zeolite and its application in synthesis of tributyl citrate

First,the hierarchical ZSM-5 zeolite was prepared by hydrothermal method using mesoporous template cetyltrimethylammonium bromide(CTAB).The physical and chemical properties of the hierarchical ZSM-5 zeolite were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and N2 adsorption-desorption and Scanning electron microscope(SEM).Then,the as-prepared hierarchical ZSM-5 zeolite and ion exchange resin were used as catalysts to evaluate the reaction performance of the synthesis of tributyl citrate.Compared with the ion exchange resin,the as-prepared ZSM-5 has a microporous and mesoporous composite structure and a large specific surface area,so that significantly improving the catalytic performance of synthesizing tributyl citrate and increasing the esterification rate of the reaction 8.7%.     

Influence of Alumina Content on Catalytic Performance of PtSn/Al2O3/SBA-15 Catalysts for Propane Dehydrogenation

The alumina-modified SBA-15 (Al2O3/SBA-15) zeolite was prepared in a non-aqueous system by using toluene as the solvent, and was used to support the PtSn-based catalyst for propane dehydrogenation. The BET surface area measurements, hydrogen chemisorption, FT-IR spectroscopy, NH3-TPD, XPS and TPO techniques were used to characterize the catalysts. Test results showed that the addition of alumina not only could modify the acid function of the support but also the structure of the metallic phase, thus affecting their catalytic properties. Among these catalysts studied, the PtSn/Al2O3 (5%)/SBA-15 catalyst exhibited a best catalytic performance in terms of propane conversion and selectivity to propene. The high catalytic performance might be attributed to the relatively good Pt metal dispersion and/or the strong interaction between Pt and Sn species.     

Characterization of Catalytic Cracking Catalysts Regenerated by Gasifying Deposited Coke

Partially or fully regenerated catalytic cracking catalysts were prepared by gasifying the coke deposited on coked catalysts with a gaseous mixture of oxygen and steam in a fixed fluidized bed(FFB).The resultant samples were characterized by different methods such as the nitrogen adsorption-desorption analysis,the X-ray diffractometry,the infrared spectroscopy,the ammonia temperature-programmed desorption(NH_3-TPD) method, the X-ray fluorescence(XRF) analysis,the transmission electron microscopy and ener...     

Propane Dehydrogenation on PtSnNa/AlSBA-15 Catalyst:Influence of Tin as a Promoter

PtSnNa/AlSBA-15 catalysts with different amounts of Sn were prepared for propane dehydrogenation.The catalysts were characterized by XRF,BET,H2 chemisorption,NH3-TPD,H2-TPR,and TPO techniques.Test results indicated that the presence of tin not only modified the acid function and the interfacial character between metal and support,but also reduced the coke deposition effectively.Among these catalysts investigated thereby,the PtSn(0.7%)Na/AlSBA-15 catalyst had the best catalytic performance in terms of propane conversion and stability.With the continuous addition of Sn,more amounts of Sn0 species appeared,which was unfavorable to the reaction.The PtSn(0.7%)Na/AlSBA-15 catalyst was parametrically characterized in order to obtain necessary information to integrate the process operating conditions.A weight hourly space velocity of 3 h-1,a reaction temperature of 610 ℃ and a H2/C3H8 molar ratio of 0.25 were found to be optimum conditions for achieving a higher dehydrogenation activity of the catalyst.     

Influence of Yttrium and Ytterbium on Reaction Performance of Platinum－Rhenium Reforming Catalyst

The influence of yttrium and ytterbium on the catalytic performance of Pt-Re refoming cata-lysts was studied in a continuous flow pressurized microreactor-chromatograph system and pilot unit.The results of micro-reactor test showed that both yttrium and ytterbium could improve the selectivity of Pt-Re catalysts for the conversion of n-heptane as well as MCP into aromatics,but also suppressed their activity as well.Pilot test results showed that yttrium and ytterbium enhanced both the selectivity and activity of Pt-Re catalysts for naphtha reforming.Yttrium showed more improvement than ytterbium.The perfor-mance difference between microreactor test and pilot test might be due to the difference in improvement of catalytic stability of yttrium or ytterbium modified Pt-Re catalysts.Yttrium and ytterbium improved the coking resistance of yttrium or ytterbium modified Pt-Re catalysts.TEM determination results indicated that both yttrium and ytterbium had improved the thermal stability of Pt-Re catalysts.     

金属氧化物对ZSM-5分子筛催化裂化性能的影响

Effects of metal oxide in ZSM-5 zeolite on its catalytic performance in fluid catalytic cracking reaction were studied via characterization by XRD and FT-IR spectroscopy using pyridine and collidine as molecular probes,and the modified ZSM-5 zeolite was evaluated in a micro reactor using standard light diesel fraction as the feedstock.Test results indicate that the metal species introduced into the ZSM-5 zeolite had led to the formation of Lewis acid centers.When the modified ZSM-5 zeolite with the metal species on its surface was used as the catalyst in FCC reaction,both the propylene yield and the propylene concentration in the liquefied petroleum gas increased,but in the meantime,more hydrogen and coke were formed at high conversion rate under the joint action of nonselective cracking of Lewis acid centers and dehydrogenation at metal centers on its outside surface.     

γ-Al2O3/SAPO-34复合催化剂及其对MTO反应的催化性能

采用介孔γ-Al₂O₃对微孔SAPO-34分子筛进行复合改性,利用水热包覆技术制备了γ-Al₂O₃/SAPO-34复合催化剂,研究了复合催化剂物化性质及其对甲醇制低碳烯烃(MTO)反应的催化性能。采用X射线衍射仪(XRD)、傅里叶红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、氨气程序升温脱附法(NH₃-TPD)和物理吸附仪(BET)等手段对不同γ-Al₂O₃/SAPO-34复合催化剂的晶相组成、骨架结构、微观形貌、表面酸性及孔结构进行分析表征。结果表明,与物理共混催化剂相比,水热包覆法制得γ-Al₂O₃/SAPO-34复合催化剂形成了包覆相和微-介孔结构(微孔比表面积123 m²/g,介孔比表面积95 m²/g)。在常压、催化剂装载量1 g、水/醇摩尔比2/1、原料进料体积空速2 h^-1、N²流速20 mL/min、反应温度380  ℃条件下,复合催化剂表现出优越的催化性能和反应寿命,甲醇转化率和低碳烯烃选择性分别达到100%和88%,催化剂寿命达到990 min,与物理共混催化剂相比,复合催化剂寿命延长了640 min。     

Y型分子筛复合材料的改性及其裂化性能

采用两交一焙的工艺对Y型分子筛复合材料(NSY)进行改性处理,采用X射线衍射、X射线荧光光谱仪、氮气吸附法、差热分析仪等测试了改性后NSY的物化性能。将改性后稀土含量不同的NSY复合材料制备催化剂,采用小型固定流化床考察了催化剂的催化裂化性能。结果表明,稀土含量高的NSY复合材料具有好的重油转化能力和高的汽柴油收率;稀土含量低的NSY复合材料具有较好的焦炭选择性和高的液化气收率。     

天然气催化燃烧催化剂的研究进展(上)

综述了近年来国内外甲烷燃烧催化剂的研究进展,包括Al2O3负载Pd、有序介孔硅负载Pd、铈基固溶体负载Pd、过渡金属氧化物负载Pd和其他载体负载Pd,负载型Pt、Au和多组分贵金属,非贵金属氧化物,钙钛矿型氧化物,类钙钛矿型氧化物,尖晶石型氧化物,烧绿石型氧化物以及六铝酸盐催化剂。讨论了这些催化剂对甲烷燃烧的活性、水热稳定性和抗硫性能,展望了研发新型高性能甲烷燃烧催化剂的未来发展趋势。     

天然气催化燃烧催化剂的研究进展(下)

综述了近年来国内外甲烷燃烧催化剂的研究进展,包括Al2O3负载Pd、有序介孔硅负载Pd、铈基固溶体负载Pd、过渡金属氧化物负载Pd和其他载体负载Pd,负载型Pt、Au和多组分贵金属,非贵金属氧化物,钙钛矿型氧化物,类钙钛矿型氧化物,尖晶石型氧化物,烧绿石型氧化物以及六铝酸盐催化剂。讨论了这些催化剂对甲烷燃烧的活性、水热稳定性和抗硫性能,展望了研发新型高性能甲烷燃烧催化剂的未来发展趋势。     

渣油悬浮床加氢裂化油溶性催化剂性能

 考察了 Mo、Ni、Co 3种自制油溶性催化剂在渣油悬浮床加氢裂化反应中的催化效果,并通过光学显微镜、激光粒度仪、XRD 和 SEM 表征了它们硫化后的性质。结果表明,在渣油悬浮床加氢裂化条件下,油溶性Mo催化剂加氢活性最高,油溶性Mo催化剂比油溶性Ni 催化剂和油溶性Co催化剂更易发生硫化,硫化后的油溶性Mo催化剂颗粒数目较多,发生了团聚现象,形成较大的颗粒,主要以MoS₂(六方晶系)晶体存在,且呈微晶状态。     

不同类型分散型催化剂对渣油催化临氢热转化过程的影响研究

采用5种不同结构、形态的催化剂进行模型化合物和实际渣油催化临氢热转化试验,考察不同催化剂催化性能差异;采用多种分析表征方法对催化剂进行物相和结构表征,以期获得造成催化剂反应性能差异的内在结构特征。研究结果表明：金属的不同形态、均相有机催化剂的有机配体都会影响菲加氢反应性能,均相有机催化剂的菲加氢活性由高到底顺序为有机Mo>有机Ni>有机Fe;低分散度、大尺寸的固体粉末铁催化剂的渣油缩合率高,生成的致密焦具有石墨碳特征;实验室自制有机钼催化剂在反应体系中生成单层或双层分散的纳米尺寸的硫化钼,具有更高的渣油裂化率和更低的缩合生焦率。     

双金属改性ZSM-5/L复合分子筛的制备及其芳构化反应性能

采用分级改性的方法制备Zn-ZSM-5/Pt-L核壳型双金属催化剂,通过改变金属负载量的组配方式对催化剂表面酸性进行调控,利用X射线衍射（XRD）、氮气吸附脱附、氨气程序升温脱附（NH3-TPD）、吡啶-原位傅里叶变换红外（Py-FTIR）等手段进行表征,并以正戊烷为原料对催化剂的轻烃芳构化性能进行评价。结果表明,在复合分子筛核壳结构的基础上,分级引入双金属的改性方式有效地调控了催化剂表面的酸分布以及L/B酸比例,使双金属催化剂更好地发挥L酸和B酸的协同催化作用,当Zn和Pt负载量分别为1.0%和0.6%时所表现出的催化性能最优,其正戊烷芳构化反应的转化率为99.1%、芳烃选择性达到47.2%。     

固定床渣油加氢脱金属催化剂的研究进展

渣油加氢脱金属(HDM)催化剂是渣油加氢技术中的核心催化剂之一,开发高性能HDM催化剂对提高固定床渣油加氢技术的劣质原料适应性以及延长装置运转周期具有重要意义。从载体、活性金属组分和助剂三方面着手,对HDM催化剂的研究进展进行了综述。首先分析了载体孔结构对HDM催化剂的影响;介绍了扩孔剂法、水热处理法、低温烧结法等Al₂O₃载体的扩孔方法。随后比较了多种活性金属组分的HDM活性,Mo表现出最佳的加氢脱金属性能,添加Co,Ni,Fe,W等金属可以在不同程度上提高催化剂的脱金属性能;总结了活性金属组分的负载方法(浸渍法、混捏法和共沉淀法)。最后简述了P、B等作为助剂对HDM催化剂活性和稳定性的影响。由此指出提高HDM催化剂的脱金属活性、容金属和抗积炭能力以及降低催化剂堆密度是HDM催化剂未来的主要研究方向。     

氯氟烃分解反应催化剂的研究进展

对有效消除氯氟烃的催化反应法(氯氟烃的加氢脱氯和催化分解)进行了评述。重点对近年来报道的用于氯氟烃加氢脱氯的负载型贵金属催化剂和用于氯氟烃催化分解的金属氧化物、SO42-促进型金属氧化物、沸石分子筛、负载型贵金属、磷酸盐等催化剂进行了总结和比较,认为磷酸盐A lPO4有望成为催化活性高、稳定性强的氯氟烃分解催化剂。