Methanol Conversion to Propylene over Mo-HZSM-5 Zeolite

2013 ◽  
Vol 834-836 ◽  
pp. 476-480
Author(s):  
Hai Rong Zhang ◽  
Hong Yan Liu ◽  
Yu Jiang ◽  
Xiao Hua Chang ◽  
Kai Yuan ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Al Content ◽  
Strong Acidity

A series of Mo-ZSM-5 zeolites have been synthesized by in site hydrothermal method and their catalytic performance for methanol conversion to propylene was tested in a fixed bed reaction at WHSV=4 h-1, pressure of 1 atm, and MeOH/H2O (mol) ratio of 1. The effect of Mo and Al content on the structure and acidity of Mo-ZSM-5 zeolites were characterized by nitrogen adsorption and NH3-TPD. The results showed that Mo incorporation gradually decreased the BET surface area and weaken the strong acidity on the surface of the zeolites. At 470 °C, the maximum selectivity of propylene and the P/E (Propylene to Ethane) ratio were achieved 45.04 % and 7.30, which were higher than those over Mo free HZSM-5 by 4.12% and 3.47, respectively. Mo-ZSM-5 zeolites are promising catalysts for methanol conversion to propylene with a high P/E.

Influence of Catalysts with Different Templates on Direct Decomposition of NO in Cement Kiln Exhaust

2018 ◽  
Vol 913 ◽  
pp. 948-953
Author(s):  
Yan Ling Gan ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Xiao Yu Ma ◽  
Ya Li Wang
Keyword(s):  
Surface Area ◽  
Decomposition Rate ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Direct Decomposition ◽  
No Decomposition ◽  
Bet Surface Area ◽  
Cement Kiln ◽  
Porous Catalyst ◽  
Decomposition Of No

The influence of catalysts with different templates on direct decomposition of NO in cement kiln exhaust was studied in this paper. The NO direct decomposition rate of porous catalyst materials with different templates was determined by infrared spectrometer. And pore structure and the microstructure of the catalysts were characterized by BET surface area, nitrogen adsorption-desorption. The results show that the catalytic performance of porous catalyst without any template is better than catalysts with other templates at low temperature. When the temperature reached 550 °C, NO decomposition rate of porous catalyst with CTAB could reach to more than 80%. And meanwhile, the catalysts with organic template reagent have higher BET surface area than those with inorganic template agent. With the increasing of the reaction time, the NO decomposition rate decreases. After reaction for 3 hours, the decomposition rate decreases from 80% to 40%.

Methanol Conversion on SAPO-34 Catalysts Synthesized by Tri-templates

2010 ◽  
Vol 1279 ◽  
Author(s):  
Liping Ye ◽  
Fahai Cao ◽  
Weiyong Ying ◽  
Dingye Fang ◽  
Qiwen Sun
Keyword(s):  
Surface Area ◽  
Crystal Size ◽  
Ammonium Hydroxide ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
High Crystallinity ◽  
Templating Agent ◽  
Mto Reaction ◽  
Small Crystal Size

AbstractThe effect of different combinations of a new tri-templating agent TEAOH/DEA/TEA, namely tetraethyl ammonium hydroxide (TEAOH)/diethylamine (DEA)/triethylamine (TEA), on the catalytic performance of SAPO-34 was investigated in MTO conversion. It was found that SAPO-34 and SAPO-5 are competing phases at TEA concentrations higher than 40 %. Pure SAPO-34 with high crystallinity, large BET surface area and small crystal size (0.8~1.4μm) was obtained at a low TEA concentrations. The combination of TEAOH/DEA/TEA strongly governed the acidity of crystals. TEAOH:DEA:TEA=0.67:0.67:0.67 gave an economical catalyst active in MTO reaction with 100 % methanol conversion, 89.39 % ethylene and propylene selectivity, a longest lifetime and a high coke capability of 24.2 wt %.

scholarly journals Hierarchical H-ZSM5 zeolites based on natural kaolinite as a high-performance catalyst for methanol to aromatic hydrocarbons conversion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Asghari ◽  
Mohammadreza Khanmohammadi Khorrami ◽  
Sayed Habib Kazemi
Keyword(s):  
Pore Size ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Low Cost ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Good Prospect

AbstractThe present work introduces a good prospect for the development of hierarchical catalysts with excellent catalytic performance in the methanol to aromatic hydrocarbons conversion (MTA) process. Hierarchical H-ZSM5 zeolites, with a tailored pore size and different Si/Al ratios, were synthesized directly using natural kaolin clay as a low-cost silica and aluminium resource. Further explored for the direct synthesis of hierarchical HZSM-5 structures was the steam assisted conversion (SAC) with a cost-effective and green affordable saccharide source of high fructose corn syrup (HFCS), as a secondary mesopore agent. The fabricated zeolites exhibiting good crystallinity, 2D and 3D nanostructures, high specific surface area, tailored pore size, and tunable acidity. Finally, the catalyst performance in the conversion of methanol to aromatic hydrocarbons was tested in a fixed bed reactor. The synthesized H-ZSM5 catalysts exhibited superior methanol conversion (over 100 h up to 90%) and selectivity (over 85%) in the methanol conversion to aromatic hydrocarbon products.

scholarly journals Catalytic Soot Oxidation Activity of NiO–CeO2 Catalysts Prepared by a Coprecipitation Method: Influence of the Preparation pH on the Catalytic Performance

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3436 ◽  
Author(s):  
Amar Bendieb Aberkane ◽  
María Pilar Yeste ◽  
Djazi Fayçal ◽  
Daniel Goma ◽  
Miguel Ángel Cauqui
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Mixed Oxide ◽  
Soot Oxidation ◽  
Catalytic Performance ◽  
Coprecipitation Method ◽  
Bet Surface Area ◽  
Mixed Oxide Catalysts ◽  
Ph Values ◽  
Tight Contact

A series of NiO–CeO2 mixed oxide catalysts have been synthesized by a modified coprecipitation method at three different pH values (pH = 8, 9, and 10). The NiO–CeO2 mixed oxide samples were characterized by TGA, XRD, inductively coupled plasma atomic emission spectroscopy (ICP-AES), FTIR, Brunauer–Emmett–Teller (BET) surface area, H2 temperature-programmed reduction (H2-TPR), and electron microscopy (high-angle annular dark-field transmission electron microscopy/energy-dispersive X-ray spectroscopy (HAADF-TEM/EDS)). The catalytic activities of the samples for soot oxidation were investigated under loose and tight contact conditions. The catalysts exhibited a high BET surface area with average crystal sizes that varied with the pH values. Electron microscopy results showed the formation of small crystallites (~5 nm) of CeO2 supported on large plate-shaped particles of NiO (~20 nm thick). XRD showed that a proportion of the Ni2+ was incorporated into the ceria network, and it appeared that the amount on Ni2+ that replaced Ce4+ was higher when the synthesis of the mixed oxides was carried out at a lower pH. Among the synthesized catalysts, Ni-Ce-8 (pH = 8) exhibited the best catalytic performance.

Effect of Catalyst Synthesis Parameters on the Performance of CO2 Hydrogenation to Methanol over SBA-15 Supported Cu/ZnO-Based Catalysts

2020 ◽  
Vol 400 ◽  
pp. 159-169
Author(s):  
Sara F.H. Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Maizatul Shima Shaharun ◽  
Duvvria Subbarao
Keyword(s):  
Surface Area ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Methanol Production ◽  
Synthesis Conditions ◽  
Metal Loading ◽  
Synthesis Parameters ◽  
Metal Support Interaction ◽  
Active Metal

Bimetallic Cu-ZnO-based catalyst were systematically prepared via impregnation technique under controlled synthesis conditions of active metal loading, ratio of active metal Cu:Zn and synthesis pH. The effect of the synthesis condition on the performance of the Cu-ZnO supported catalysts with respect to the hydrogenation of CO2 to methanol in micro-activity fixed-bed reactor at 250°C, 2.25 MPa, and 75% H2/25%CO2 ratio. The synthesized catalysts were characterized by transmission electron microscopy (TEM) and temperature programmed desorption, reduction, oxidation and pulse chemisorption (TPDRO) and the surface area determination was also performed. The results demonstrate that the catalytic structure, activity, and methanol selectivity was strongly affected by the synthesis parameters. Increasing of synthesis pH from 1 to 7 shows better metal particles distribution, Cu desperation of 29%, higher BET surface area as well as Cu surface area, while further increasing on pH revealed on particles agglomeration and weak metal-support interaction. In addition, increasing of the active metal loading from 5 to 15 % resulted in dramatic increase in the conversion of CO2 and methanol production while further increase caused lower catalytic performance. Moreover, catalyst with total loading of 15%, Cu:Zn ratio of 70:30 synthesized at pH of 7 exhibit higher catalytic activity of 14%, methanol selectivity of 92%, and TOF of 1.24×103 s-1 compared with other catalyst prepared under various conditions

Synthesis of Carbon Nanofiber-Titania-Cordierite Monolith Composite and its Application as Catalyst Support on Citral Hydrogenation

2012 ◽  
Vol 535-537 ◽  
pp. 178-185 ◽  
Author(s):  
Jie Zhu ◽  
Ming Shi Li ◽  
Mo Hong Lu
Keyword(s):  
Surface Area ◽  
Carbon Nanofiber ◽  
Sol Gel ◽  
Catalyst Support ◽  
Textural Properties ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
Citral Hydrogenation

We reported the synthesis of a promising carbon nanofiber-titania-cordierite monolith composite (C/TiO2/monolith) and its application in citral hydrogenation. The composite was synthesized through two steps: TiO2 coating on the surface of the monolith with sol-gel method and the following carbon deposit by methane decomposition. C/TiO2/monolith was subsequently employed to prepare its supported palladium catalyst, Pd/C/TiO2/monolith and its catalytic performance was evaluated in selective hydrogenation of citral. Results revealed that 2.0 wt% tetrabutyl titanate sol in composite synthesis was the best in improving textural properties of C/TiO2/monolith. The optimal composite possessed a BET surface area of 39.4 m2/g and micropore area accounted for only 3.8% of its total BET surface area. It contained about 30 wt% of carbon, which was mainly composed of carbon nanofiber. Pd/C/TiO2/monolith exhibited the high citronellal selectivity (81%) at 90% citral conversion, which was attributed to the decrease of internal diffusion limitation due to its mesoporous structure.

Effect of Silica Base Catalyst on Transformation of Methanol to Hydrocarbon

2017 ◽  
Vol 751 ◽  
pp. 512-517 ◽  
Author(s):  
Supranee Lao-Ubol ◽  
Phunthinee Somwongsa ◽  
Pracha Laoauyporn ◽  
Pasinee Panith ◽  
Siriporn Larpkiattaworn ◽  
...  
Keyword(s):  
Pore Diameter ◽  
Fixed Bed ◽  
Methanol Conversion ◽  
Liquid Hydrocarbon ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Fixed Bed Reactor ◽  
Phosphorus Species ◽  
Methanol To Hydrocarbon

Five different types of silica catalyst (SBA-15, SBA-15-PO3H2, and three different Si/Al ratio of commercial zeolites (30, 80 and 280) were used to study the transformation of methanol to hydrocarbon (MTH). The aim of this study was to investigate the effect of pore diameter and acidity in the structure of silica catalysts on the process performances in terms of methanol conversion and hydrocarbon selectivity. The mesoporous silica catalysts were prepared by co-condensation method. The catalysts samples were characterized by GC-MS, XRD, BET, and NH3-TPD techniques. The catalytic performance of synthesized and commercial catalysts for MTH process was evaluated using a homemade fixed bed reactor at temperature (300°C). It was found that the liquid hydrocarbon product provided by zeolite catalysts is aromatic hydrocarbons-rich. High Si/Al zeolites with larger pore size lead to higher selectivity and yield to paraffins (C1-C7). In contrast to commercial zeolite catalyst, SBA-15 and its modification with phosphorus species showed no conversion under studied condition. These results indicate that both pore diameter and acidity influence the product distribution in methanol to hydrocarbon process.

An Experimental Analysis of Lactic Acid Esterification Process Using Langmuir-Hinshelwood Model

2017 ◽  
Vol 733 ◽  
pp. 36-41
Author(s):  
Edidiong Okon ◽  
Habiba Shehu ◽  
Edward Gobina
Keyword(s):  
Lactic Acid ◽  
Cation Exchange ◽  
Pore Size ◽  
Surface Area ◽  
Cation Exchange Resin ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Gas Chromatography Mass Spectrometry ◽  
Type Iv ◽  
Exchange Resins

In this study, esterification of lactic acid and ethanol to produce ethyl lactate using different cation-exchange resin catalysts was performed at 100 °C. The catalysts used for the esterification process were amberlyst 16 and dowex 50W8x cation-exchange resins. Two simplified mechanisms based on Langmuir-Hinshelwood model were employed to describe the components that adsorbed most on the surface of the catalysts. Fourier Transform Infrared (Nicolet iS10 FTIR) was employed to verify the rationality of the mechanisms. FTIR of the esterification product reflected C=O, H=O and C=C bonds on the spectra confirming water and ethanol as the most adsorbed components. The kinetic study of the retention time and the peak areas of the esterification produced with the different catalysts were compared using an autosampler gas chromatography/mass spectrometry (autosampler GC-MS). The chromatogram of the esterification product catalysed by amberlyst 16 showed a faster elution at 1.503 mins with the peak area of 1229816403 m2 in contrast to the dowex 50W8x. The BET surface area and BJH pore size distribution of the resin catalysts were determined using liquid nitrogen adsorption (Quantachrome, 2013) at 77 K. The BET surface area results of amberlyst 16 resin catalysts was found to be 1.659m2/g compared to 0.1m2/g for the dowex 50W8x. The BJH results of the catalysts exhibited a type IV isotherm with hysteresis confirming that the materials were mesoporous with pore size in the region of 2 – 50 nm.

scholarly journals Comparison of Nitrogen Adsorption and Mercury Penetration Results. Pore Size Distributions for a Series of Mo-A12O3 Catalysis with Increasing MoO3 Content

1987 ◽  
Vol 4 (1-2) ◽  
pp. 87-104 ◽  
Author(s):  
Bruce D Adkins ◽  
Jill B. Heink ◽  
Burtron H. Davis
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
Three Dimensional ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Size Distributions ◽  
Electron Microscopic ◽  
Pore Size Distributions ◽  
Electron Microscopic Data ◽  
Penetration Data

Scanning electron microscopic data, X-ray diffraction patterns and porosity measurements are consistent with a structure for an Mo-A12O3 catalyst series containing a single surface layer of Mo up to the point where the Mo loadings exceed the amount required for a monolayer. For greater Mo loadings than required for a monolayer, three dimensional orthorhombic MoO3 is also present. The cumulative pore volume, on an alumina basis, does not appear to be significantly altered by MoO3 loadings up to about 15 wt.%. The BET surface area, on an alumina basis, remains constant with Mo loading. However, the apparent surface area calculated from mercury penetration data decreases with Mo loading. For these materials with cylindrical pores, the Broekhoff-deBoer model for the calculation of pore size distributions produced closer agreement to the mercury penetration pore size distribution. This is in contrast to materials composed of nonporous spheres where the Broekhoff-deBoer model provided poorer agreement to mercury penetration results than either the Cohan or a packed sphere model. The results show that, within a factor of two the pore size distributions calculated from nitrogen adsorption and mercury penetration data are comparable.

Characterization of Novel Sorbents for Mercury Removal at Elevated Temperature

2015 ◽  
Vol 656-657 ◽  
pp. 23-27
Author(s):  
Han Wen Cheng ◽  
Ching Tsung Yu
Keyword(s):  
Elevated Temperature ◽  
Transition Metals ◽  
Surface Area ◽  
Fixed Bed ◽  
Elemental Mercury ◽  
Fixed Bed Reactor ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Retention Capacity

The novel carbonate sorbents of Mg–Al–CO3 and (Mg3−x, Cux)–Al–CO3, were synthesized by co-precipitation method with individual nitrate salt of metal ions under alkaline conditions. The synthetic sorbent was characterized by analysis techniques such as BET surface area analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Elemental mercury capture experiments were carried out in a fixed-bed reactor including Hg permeation source, furnace, and Hg analyzer, which was conducted at temperature ranging from 30 to 300 o C. The major results showed that the surface area of material was significantly increased via incorporating Cu2+ into Mg–Al–CO3, accordingly enhancing Hg retention capacity of sorbents. SEM imagines displayed the layer appearance of Mg/Al and Mg/Cu/Al sorbents. Crystalline analysis indicated lamella structure accompanied with metal oxides within materials. Mercury removal tests demonstrated that the breakthrough time increased with temperature by adding transition metals to Mg–Al–CO3 as (Mg3−x, Cux)–Al–CO3. Hg uptake by the (Mg3−x, Cux)–Al–CO3 sorbent rapidly increased with elevated temperature up to 200 o C and reached the maximum capacity of 12.93 μg/g, and then gradually decreased after 300 o C. Surface area and unique properties of transition metals are the reason toward improving Hg capture sorbent. These results represent the feasibility of using such Hg sorbents for elemental mercury removal under elevated temperature conditions, and the detail mechanism is needed to be further studied.

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