COMBINED EFFECT OF FLUORINE AND ZINC INCORPORATION ON THE HDS ACTIVITY OF Co-Mo CATALYSTS

Conventional HDS-catalysts consist of Co and Mo supported on Y-Al₂O₃. The addition of Zn as a second promoter or the alumina acidification with F increase the catalitye activity in HDS of commercial feeds (Fierro et al., 1984; Boorman et al., 1984). In this paper the combined effect of both Zn and F incorporation is discussed. A series of Zn-Co-Mo catalysts supported on fluorinated alumina (0.0 -2.0 wt% F) was prepared and tested for HDS activity using a commercial gas-oil. The data gathered showed a decrease in HDS activity for intermediate F contents (0.4 - 1.0 wt%). This result could be tentatively explained through alumina surface deterioration during impregnation with NH₄HF₂ solutions al low pH.     

Design of Catalyst Support for Deep Hydrodesulfurization of Gas Oil

Abstract

Alumina-silica (Al₂O₃-SiO₂) composite supports were examined to find the optimum state of support (i.e., composition and morphology). SiO₂ content in the Al₂O₃-SiO₂ support induced a shift of the main peak to higher frequency ascribed to an increased amount of Mo₈O₂₆ ^4?. A 75 wt% Al₂O₃-25 wt% SiO₂ support had homogeneously dispersed alumina particles of smaller size with high crystallinity. Hydrodesulfurization (HDS) of straight-run gas oil and its conventionally hydrotreated straight-run gas oil was performed over NiMo sulfides supported on Al₂O₃-SiO₂ composites. The high crystallinity of NMASA2-27 may be related to the high HDS and hydrogenation activity of NiMo sulfides due to its moderate interaction with the alumina surface.     

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.     

Hydrodesulfurization,Hydrodenitrogenation, Hydrodemetallization,and Hydrodeasphaltenization of Maya Crude over NiMo/Al2O3 Modified with Ti and P

Abstract

The effect of adding Ti (4.5 wt%) and P (～1.0 wt%) by several routes to a NiMo/ab Al₂O₃ catalyst on the hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM), and hydrodeasphaltenization (HDAs) of heavy Maya crude was investigated. The results show that not all the catalyst functionalities respond equally well to the addition of Ti and P to the catalyst formulation. There is not a single catalyst formulation that can achieve optimum performance in all the catalyst functionalities. For HDS, Ti incorporation increases activity but the route by which P is added afterwards can improve or be detrimental to HDS activity. For HDN, the incorporation of P to the catalyst can lead to significant improvements in catalytic activity and catalyst stability. Ti increases HDM activity but the addition of P to the catalyst is detrimental to this functionality. For the elimination of asphaltenes, the catalyst supported on pure alumina is the best. So for HDAs, no benefit is obtained by the addition of Ti or P to the catalyst. Textural properties are important and HDM and HDAs increase with catalyst average pore diameter. Hydrodemetallization activity increases with the acidity of the catalyst.     

IRON COMPOUNDS AND C0-Mo/Al2O3 CATALYSTS: ACTIVITY IN DIRECT HYDROGENATION OF A SUBBITUMINOUS A COAL WITH AN H-DONOR SOLVENT

Abstract

The effectiveness of different catalysts were compared in coal liquefaction experiments using a 250 ml stirred autoclave, 10 g of a Spanish Subbituminous A coal, 1 hour reaction time, 17 MPa operating pressure, 400 rpm stirring speed, at 425 and 450 °C with 2/1 and 3/1 tetralin/coal ratio. The liquefaction products were fractionated into oils, asphaltenes, preasphaltenes and solid residue using pentane, toluene and THF as extractive solvents. Three iron-oxide containing catalysts: red mud, an Fe2O3 aerosol and Cottrell ash (by-product of the aluminium industry); and three alumina supported catalysts: CMA, which is a conventional CoMo/Al2O3 catalyst, CZMA which in addition contains Zn as a second promoter, and CZMFA which has the alumina acidified with fluorine and also contains Zn, were compared. It has been reported that the addition of Zn and of F enhances the HDS, cracking, hydrocracking or hydrogenating activities of CoMo/Al2O3 catalysts in experiments with pure compounds. The objective of this study was to determine if the addition of Zn and of F has also a beneficial effect in the catalyst activities in coal liquefaction, and also to compare cheap iron containing catalysts with the more sophisticated and expensive alumina supported ones.

The results showed that 1) Catalysts effects depend on the operating conditions used, and that with tetralin, a strong H-donor solvent, they never are very pronounced. 2) The supported catalysts have higher activities in coal liquefaction than the iron ones, but there are no significant differences among the catalysts within each group. 3) Zn, which is a cheaper metal than Co, can substitute succesfully for half the amount of Co and retain the activity of the CoMo/Al2O3 catalyst in coal liquefaction. 4) The addition of F to the CoMo/Al2O3 catalyst does not show a benefecial effect     

硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。     

KINETIC INVESTIGATION OF METHYLCYCLOPENTANE REFORMING ON FRESH AND DEACTIVATING Pt/Al2O3 CATALYST

ABSTRACT

The conversion of methylcyclopentane (MCP) in hydrogen on fresh and deactivating Pt/Al₂O₃ catalyst to hydrogenolysis products (2-methylpentane, 3-methylpentane and n-hexane), cyclohexane and benzene was studied in a Berty CSTR at various partial pressures of MCP and H₂, and at a total pressure of 1 atm. For the kinetic studies, temperatures between 370 – 400° and W/F values up to 0.33 g min/cm³ were used. The conversion of MCP was found to increase with increase in temperature at all the MCP partial pressures investigated. The hydrogenolysis products and benzene composition generally increased with increase in temperature and W/F. The mechanism for the reforming of MCP was similar to that proposed by Dartigues et al. (1978) except that the formation of hydrogenolysis products was accounted for in this formulation. Eleven rate models were developed and tested and six satisfied the set criteria. Since hydrogenation/dehydrogenation and desorption steps are relatively rapid, the conversion step to hydrogenolysis products was deemed the only rate determining step with an activation energy of 36.31 kcal/gmol. For the deactivation studies, the model of Corella and Asua (1982) was used for the development of two deactivation models. The only model found to predict the deactivation behavior was the step leading to the formation of the coke precursor as rate controlling.     

The Support Effect on Hydrogenolysis of Thiophene and Gas–Oil

Abstract

Results are reported on the support effect on the catalytic activity in thiophene hydrodesulfurization (HDS) of sulfided Ni-Mo catalysts supported on pure niobia, mixed oxides of Nb₂O₅-TiO₂ prepared by sol-gel method, and Nb₂O₅/TiO₂ and Nb₂O₅/Al₂O₃ prepared by surface deposition. The prepared samples were characterized using N₂ adsorption at ?196°C, X-ray diffraction (XRD), and temperature-programmed reduction (TPR) techniques. This study showed activity variation as a function of support composition. The activity of niobia-rich catalysts was no longer promoted by the synergy between Ni and Mo. The absence of synergy between molybdenum and nickel on niobia can be explained by the strong interaction of each metal with niobia at the expense of interaction with each other. It was found that 5 wt% Nb₂O₅/TiO₂-supported catalyst was the better catalyst for thiophene HDS. It was shown that by means of an adequate support design it is possible to significantly increase the functionalities of HDS catalysts. Semiconducting supports like TiO₂ can improve the HDS activity by exerting electronic effects on the active phase, helping in this way the formation of sulfur vacancies. The 5 wt% Nb₂O₅/TiO₂ was also tested at high pressure with gas oil feedstock. It is observed with the hydrogeolysis of sulfur compounds against time-on-stream that the activity of this catalyst decreases fast with time.     

Desulfurization of FCC Gasoline Over Mordenite Modified with Al2O3

Abstract

Mordenite modified with Al₂O₃ (Al₂O₃/mordenite) was synthesized and used for the desulfurization of FCC gasoline. The influences of operating parameters on the results were studied for the model solution composed of dibenzothiophene (DBT) and isooctane. Al₂O₃/mordenite exhibits higher sulfur capacity than other kinds of chemisorbents. The suitable composition of the chemisorbent is 30 wt% Al₂O₃ to 70 wt% mordenite. The optimal operating parameters are: temperature 160°C; velocity 3 h^?1 (WHSV). Under the stated conditions, desulfurization was carried out for the FCC gasoline with sulfur content of 220.4 μg/g. The chemisorbent can maintain the sulfur content under 50 μg/g for 40 h and has good regeneration ability after desorption using benzene.     

The surface properties of aluminated meso–macroporous silica and its catalytic performance as hydrodesulfurization catalyst support

Aluminated mesoporous silica was prepared by multiple post-grafting of alumina onto uniform mesoporous SiO_2 ,which was assembled from monodisperse SiO_2 microspheres.Hydrodesulfurization(HDS)catalyst was prepared by loading Ni and Mo active components onto the aluminated uniform mesoporous SiO_2 ,and its HDS catalytic performance was evaluated using hydrodesulfurization of dibenzothiophene as the probe reaction at 300°C and 6.0 MPa in a tubular reactor.The samples were characterized by N_2 physisorption,scanning electronic microscopy,Fourier transform infrared spectrum,X-ray diffraction(XRD),temperature-programmed desorption of ammonia(NH_3-TPD),~(27)Al nuclear magnetic resonance(~(27)Al-NMR)and high-resolution transmission electron microscopy(HRTEM).The results showed that the Si–OH group content of SiO_2 was mainly dependent on the pretreatment conditions and had significant influence on the activity of the Ni Mo catalyst.The surface properties of the aluminated SiO_2 varied with the Al_2O_3-grafting cycles.Generally after four cycles of grafting,the aluminated SiO_2 behaved like amorphous alumina.In addition,plotting of activity of Ni Mo catalysts supported on aluminated meso–macroporous silica materials against the Al_2O_3-grafting cycle yields a volcano curve.     

Applying Pebax-1657/ZnO mixed matrix membranes for CO2/CH4 separation

Abstract

Membrane technologies as conservative approaches have absorbed much attention in chemical and petroleum engineering, recently. The current research presents the preparation of effectively mixed matrix membranes (MMMs) using polyether-block-amide (Pebax-1657) as a polymeric matrix and zinc oxide (ZnO) nanoparticles with various contents (0.0, 2.5, 5.0, 7.5, and 10.0?wt%) as a filler. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and field emission scanning microscopy (FESEM) were conducted to characterize the prepared membranes. The membrane performance was evaluated by caring out permeation experiments of the CO₂ and CH₄ at a pressure of 3?bar and temperature of 30?°C. Based on the obtained results, the CO₂ permeability and ideal CO₂/CH₄ selectivity increased about 13 and 21%, respectively at 10.0?wt% loading of ZnO in the polymer matrix.     

Operation Parameters on CO2-Foam process

Abstract

Reducing the mobility of CO₂ by means of generating in situ foam is an effective method for improving the oil recovery in CO₂ flooding processes. Implementation of the CO₂-foam technique typically involves the co-injection of CO₂ and surfactant solution into the porous medium. The surfactant molecules form bubble films that trap the flowing CO₂ molecules. The effectiveness of the CO₂-foam process is measured in terms of foam mobility. The mobility of CO₂-foam is affected by different operation parameters, such as pressure, temperature, foam quality, and brine concentration. However, surfactant type governs the overall efficiency of the CO₂-foam process. This paper presents the results of a series of experiments conducted to study the effect of various parameters on the CO₂-foam process. Bottle tests were conducted for four commercially available surfactants and among them, Chaser CD-1045 was found to be the most effective surfactant for CO₂-foam flow under reservoir conditions. It was observed that an increase in pressure from 1, 200 psi to 1, 500 psi leads to increase of the mobility of CO₂-foam, and an increase in temperature from 72 to 122°F reduces the mobility. Also, as the foam quality increases from 20 to 80%, the mobility decreases. It was observed that there was no significant effect on the mobility with an increase in brine concentration from 1 to 3 wt%.     

Petroleum Hydrocarbons Extraction Efficiency of Carbon Tetrachloride and Trichlorotrifluoroethane: A Comparative Study

Abstract

Petroleum hydrocarbons (PHC) contaminated water samples, prepared in laboratory, were analyzed using infrared spectroscopy to compare PHC extraction efficiency of carbon tetrachloride (CCl₄) and trichlorotrifluoroethane (C₂Cl₃F₃) solvents. The comparison of the results illustrated that PHC extraction efficiency of CCl₄ was greater than C₂Cl₃F₃. The higher extraction efficiency of CCl₄ was ascribed to its more non-polar nature and higher polarity index. This study supported the selection and use of CCl₄ for extraction and quantification of PHC of groundwater samples of the projects carried out in the department.     

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.     

Ammonium perchlorate-based molecular perovskite energetic materials: preparation,characterization, and thermal catalysis performance with MoS2

ABSTRACT

In this study, ammonium perchlorate (AP)-based molecular perovskite structural high-energetic materials (H₂dabco)[NH₄(ClO₄)₃] (DAP) were fabricated and their catalytic performance upon the addition of MoS₂ nanosheets was investigated. The DAP samples were succesfully prepared via a self-assembly reaction and their morphology and structure were characterized via scanning electron microscopy, X-ray diffractometry, and Fourier transform infrared spectroscopy. The thermal decomposition performance of a pure DAP sample and of a mixture of DAP with MoS₂ nanosheets were analyzed via differential scanning calorimetry. The results show that DAP has a high thermal stability at its initial decomposition temperature of 319.8°C, and that its apparent decomposition heat measures 4199 J/g. This value is higher than for AP (829.7 J/g). Furthermore, the thermal decomposition peak temperature of DAP upon the addition of 1 wt% and 3 wt% MoS₂ nanosheets decreases from 394.4°C to 343.3°C and 328.8°C, respectively. The investigation of the catalysis thermal performance of DAP may foster its practical application in composite propellant.     

Dibenzothiophene Hydrodesulfurization Activity of MoS2 Supported in Sol–Gel ZrO2–TiO2 Mixed Oxides

Abstract

In this work, we report the effect of support composition on the properties of MoS₂ impregnated in sol–gel ZrO₂–TiO₂ mixed oxides as dibenzothiophene hydrodesulfurization catalyst. The supports calcined at 500°C were characterized by N₂ physisorption and X-ray diffraction (electronic radial distribution function). The oxidic impregnated materials (2.8 Mo atoms/nm²) were sulfided at 400°C under a H₂S/H₂ stream. The sample impregnated on the equimolar support showed the highest activity per mass of catalysts whereas the one with TiO₂ carrier was superior in a per mass of Mo basis. Marked differences in products selectivity were observed by TiO₂ addition in the supports. The hydrodesulfurization route to partially hydrogenated compounds was favored over the mixed oxides-supported catalysts meanwhile the direct desulfurization (to biphenyl) was promoted on the ZrO₂-supported solid. It is suggested that among other properties the dispersion and morphology of the MoS₂ phase could influence that behavior.     

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%。     

IRON COMPOUNDS AND C0-Mo/Al2O3 CATALYSTS: ACTIVITY IN DIRECT HYDROGENATION OF A SUBBITUMINOUS A COAL WITH AN H-DONOR SOLVENT

The effectiveness of different catalysts were compared in coal liquefaction experiments using a 250 ml stirred autoclave, 10 g of a Spanish Subbituminous A coal, 1 hour reaction time, 17 MPa operating pressure, 400 rpm stirring speed, at 425 and 450 °C with 2/1 and 3/1 tetralin/coal ratio. The liquefaction products were fractionated into oils, asphaltenes, preasphaltenes and solid residue using pentane, toluene and THF as extractive solvents. Three iron-oxide containing catalysts: red mud, an Fe2O3 aerosol and Cottrell ash (by-product of the aluminium industry); and three alumina supported catalysts: CMA, which is a conventional CoMo/Al2O3 catalyst, CZMA which in addition contains Zn as a second promoter, and CZMFA which has the alumina acidified with fluorine and also contains Zn, were compared. It has been reported that the addition of Zn and of F enhances the HDS, cracking, hydrocracking or hydrogenating activities of CoMo/Al2O3 catalysts in experiments with pure compounds. The objective of this study was to determine if the addition of Zn and of F has also a beneficial effect in the catalyst activities in coal liquefaction, and also to compare cheap iron containing catalysts with the more sophisticated and expensive alumina supported ones.

The results showed that 1) Catalysts effects depend on the operating conditions used, and that with tetralin, a strong H-donor solvent, they never are very pronounced. 2) The supported catalysts have higher activities in coal liquefaction than the iron ones, but there are no significant differences among the catalysts within each group. 3) Zn, which is a cheaper metal than Co, can substitute succesfully for half the amount of Co and retain the activity of the CoMo/Al2O3 catalyst in coal liquefaction. 4) The addition of F to the CoMo/Al2O3 catalyst does not show a benefecial effect     

Hydrodesulfurization, Hydrodenitrogenation, Hydrodemetallization, and Hydrodeasphaltenization of Maya Crude over NiMo/Al2O3 Modified with Ti and P

The effect of adding Ti (4.5 wt%) and P (∼1.0 wt%) by several routes to a NiMo/ab Al₂O₃ catalyst on the hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM), and hydrodeasphaltenization (HDAs) of heavy Maya crude was investigated. The results show that not all the catalyst functionalities respond equally well to the addition of Ti and P to the catalyst formulation. There is not a single catalyst formulation that can achieve optimum performance in all the catalyst functionalities. For HDS, Ti incorporation increases activity but the route by which P is added afterwards can improve or be detrimental to HDS activity. For HDN, the incorporation of P to the catalyst can lead to significant improvements in catalytic activity and catalyst stability. Ti increases HDM activity but the addition of P to the catalyst is detrimental to this functionality. For the elimination of asphaltenes, the catalyst supported on pure alumina is the best. So for HDAs, no benefit is obtained by the addition of Ti or P to the catalyst. Textural properties are important and HDM and HDAs increase with catalyst average pore diameter. Hydrodemetallization activity increases with the acidity of the catalyst.     

Research and Field Application of Polymer-Multiple Emulsion Crosslinker Gel for the Deep Profile Control

The authors describe a means to prolong gel time of Cr(Ac)₃-polyacrylamide gel system by coating the Cr(Ac)₃, forming the W₁/O/W₂ crosslinker. The white oil is the oil phase, and the sorbitol fatty acid esters are the water-in-oil emulsifier. The polyoxyethylene sorbitan monostearate is the oil-in-water emulsifier, which has a national patent (cf. Wang et al., 2009). The authors researched the effect of the reactants concentrations and reservoir environments are investigated to gelling behavior and plugging capacity such as temperature, salinity, and permeability. Compared to the Cr(Ac)₃ without coating, the multiple emulsion crosslinker obviously delays crosslinking and greatly increases gel time by about 3–4 times, so it is conducible to deep profile control. Reactant concentrations and temperature increase the gel strength and plugging capacity, but shorten gel time. Salinity causes gel time to shorten and lengthen, and gel strength weakens before it increases. Permeability reduces the plugging capacity and presents in linear relation in the log-log coordinate. Four wells were tested successfully in Shengli Oilfield from May to November 2008. The average injection pressure-added is 2.5 MPa, and approximately 3,200 tons of incremental oil was obtained with 6% water-cut decrease.