Download or read book Synthesis and Characterization of Cobalt Supported TiO2 with Mn Zn Zr Promoters for Fischer Tropsch Synthesis written by Mohamad Firdaus Mohamad Ghazali and published by . This book was released on 2012 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research about the synthesis and characterization cobalt supported TiO2 catalyst for Fischer-Tropsch synthesis (FTS) producing clean and best fuel. In variety of type of promoters, the effect is determined. The catalytic material will be prepared by impregnation of a mesoporous molecular sieve based on silica which is TiO2 as cobalt catalytic supporters and Zn/Zr/Mn as promoters for comparison purposes. All materials will be used characterizing by several physico-chemical techniques such as SEM, , TGA, FTIR. The catalytic and characterization results achieve give a great influence of mesoporous support porosity on the structure, reducibility and Fischer-Tropsch synthesis catalytic behavior of cobalt oxide species supported over these ordered materials. The size of supported cobalt oxide species formed during the calcination step increased with the average pore size (Dp) of the mesoporous support. Thus, the catalyst with larger Co oxide species located in wide pore silica showed to be easily reducible, more active and very selective toward the fuel fraction. The additional of promoters will be used to increase the performances of Fischer-Tropsch synthesis.

Download or read book Effect of Promoters Mn Zn and ZrO2 on the Characterization of SBA 15 Supported Cobalt Catalyst for Fischer tropsch Synthesis written by Muhammad Suhaimi Man and published by . This book was released on 2012 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fischer-Tropsch synthesis (FTS) is a part of gas-to-liquids (GTL) technology, which produces synthetic liquid hydrocarbons from natural gas. Recently the production of clean fuels and particularly of synthetic diesel by means of the FTS process has aroused renewed interest in both industrial and academic field. This process was shown to be catalyzed by certain transition metals, such as Co which present the highest activity. This research work is about the synthesis of SBA-15 and preparation of catalyst with different promoter Zr, Zn, Mn - Co based supported by SBA-15 by wet impregnation catalysts and characterizes all sampling. All materials were characterized by several physico-chemical techniques such as TGA, SEM and FTIR. The catalytic and characterization results show a great influence of mesoporous support porosity on the structure, reducibility and FTS catalytic behavior of cobalt oxide species supported over these ordered materials. After modification of SBA-15 by Co with different loading, the particles found to be attached closely with each other. The SEM picture shows a large number of SBA-15 particles attaching closely with one another. So this will make catalyst more efficient and effective during FT process. Then, using FTIR, the functional groups will be observed with certain wavelength in the samples such as cobalt oxides, Si-O-Si, Si-CH3, zinc oxide, OH band, Si-C, and others. Besides that, the identification of metal inside SBA-15 was determined by comparing the pure SBA-15 with the incorporated metal on SBA-15. For this research, the characterization of the catalyst by selecting Zn as promoter have quiet similar characterization with noble metal that already investigate.

Download or read book Preparation and Characterization of Cobalt Based and Zinc Promoted Catalyst Fro Fisher Tropsch Synthesis written by Nur Hayati Zulkefli and published by . This book was released on 2011 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research is to compare the characterization of SBA-15 and TiO2 supported cobalt catalyst for Fischer-Tropsch synthesis based on effect of cobalt loading. In order to complete this research, the catalyst must be prepared by incipient wetness impregnation method. The catalysts were prepared with different cobalt loading, which are 5%, 10% and 15% and using zinc as a promoter. To characterize these catalysts, different methods were used. First of all, characterization of SBA-15 and TiO2 were compared by using Fourier Transform Infrared Spectroscopy (FTIR). Then the catalysts were tested using Scanning Electron Microscope (SEM). Through this characterization, the surface of catalysts was compared. The surface structure of Co/SBA-15 is more ordered when compared to Co/TiO2 catalyst. This is compared by the SEM image taken. Therefore, Co/TiO2 is also a good catalyst with advantages when compared to Co/SBA-15 catalyst. The conclusion of this research when comparing the characterization of Co/SBA-15 and TiO2 catalysts, is Co/SBA-15 catalyst is a good catalyst when compared to Co/TiO2 catalyst.

Download or read book Fischer Tropsch Cobalt Catalyst Improvements with the Presence of TiO2 La2O3 and ZrO2 on an Alumina Support written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to evaluate the effect of titanium oxide, lanthanum oxide, and zirconium oxide on alumina supported cobalt catalysts. The hypothesis was that the presence of lanthanum oxide, titanium oxide, and zirconium oxide would reduce the interaction between cobalt and the alumina support. This was of interest because an optimized weakened interaction could lead to the most advantageous cobalt dispersion, particle size, and reducibility. The presence of these oxides on the support were investigated using a wide range of characterization techniques such as SEM, nitrogen adsorption, x-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed reduction after reduction (TPR-AR), and hydrogen chemisorptions/pulse reoxidation. Results indicated that both La2O3 and TiO2 doped supports facilitated the reduction of cobalt oxide species in reference to pure alumina supported cobalt catalysts, however further investigation is needed to determine the effect of ZrO2 on the reduction profile. Results showed an increased corrected cluster size for all three doped supported catalysts in comparison to their reference catalysts. The increase in reduction and an increase in the cluster size led to the conclusion that the support-metal interaction weakened by the addition of TiO2 and La2O3. It is also likely that the interaction decreased upon presence of ZrO2 on the alumina, but further research is necessary. Preliminary results have indicated that the alumina-supported catalysts with titanium oxide and lanthanum oxide present are of interest because of the weakened cobalt support interaction. These catalysts showed an increased extent of reduction, therefore more metallic cobalt is present on the support. However, whether or not there is more cobalt available to participate in the Fischer-Tropsch synthesis reaction (cobalt surface atoms) depends also on the cluster size. On one hand, increasing cluster size alone tends to decrease the

Download or read book Metal Oxide Promotion of Cobalt Based Fischer Tropsch Synthesis Catalysts written by Gregory Robert Johnson and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic fuel production by means of Fischer-Tropsch synthesis (FTS) involves the catalytic hydrogenation of CO over Co-based catalysts. Often, these catalysts incorporate performance-enhancing additives known as promoters. Although not catalytically active for FTS by themselves, promoters can alter the structural and electronic properties of the active Co metal so as to improve catalyst activity, selectivity, or stability. Elements that form metal oxides have been studied for their ability to increase CO consumption rates and shift the product distribution toward higher molecular weight. Despite several decades of study of such elements, there remains limited understanding of the connections between these promotional effects and element properties. Accordingly, this dissertation focuses on clarifying the chemical basis for the effects of metal oxide promotion and making connections to periodic trends. To understand the importance of physical contact between the promoter and the Co, the influence of Co-Mn spatial association on the magnitude of Mn promotional effects was investigated. Elemental maps obtained by STEM-EDS revealed that different catalyst pretreatment methods could control how closely associated the promoter and Co were at the nanoscale. By relating these results to catalytic reaction data, it was determined that higher extents of contact between the two elements were correlated with higher selectivities toward C5+ hydrocarbons. This work was extended to the elements Ce, Gd, La, and Zr, which are among the most commonly studied metal oxide-forming promoters. The presence of the promoter element suppressed methane formation and increased the FTS chain propagation probability, but the sensitivity of these effects toward promoter loading was different for each element. Elements that deposited preferentially onto the Co nanoparticles led to rapid shifts in the product distribution as the promoter loading increased, whereas elements that dispersed over the entire catalyst surface resulted in more gradual changes. For all promoters, the product selectivities became insensitive to loading when the loading reached a quantity nearly equivalent to that which would form a half monolayer of the promoter on the Co nanoparticle surface. These trends are characteristic of the formation of active sites along the interface between the Co and the promoter that exhibit improved product selectivity. Structurally, the oxidation states and local coordination environments of the promoters were consistent with highly dispersed oxides. No evidence for the formation of bimetallic alloys or large promoter-containing crystallites was detected by either X-ray absorption spectroscopy or X-ray diffraction. These data suggest that small promoter oxide moieties decorate the surface of the Co metal nanoparticles so as to form metal-metal oxide interfaces. Under this model, the promotional effects increase in magnitude as the fraction of Co active sites that are adjacent to the promoter increases. When the Co surface is sufficiently covered by the promoter so that the fraction of active sites that are along the perimeter of the promoter moieties is nearly unity, the catalyst performance ceases to improve as a function of promoter loading. Guided by this reasoning, the catalytic properties of the promoted catalysts were investigated using samples in which the fraction of sites that were promoted was near unity. Measurements of reaction kinetics were conducted to assess the impact of metal oxide promotion on the rate parameters governing FTS. The rates of CO consumption for both unpromoted and metal oxide-promoted catalysts followed a Langmuir-Hinshelwood rate law for which H-assisted CO dissociation is assumed to be the rate determining step. Each promoter increased the apparent rate constant and the CO adsorption constant that appear within the rate law. Thus, metal oxide promotion appears both to facilitate the cleavage of the C-O bond and to enhance the extent of CO adsorption onto the catalyst. This finding was reinforced by CO temperature programmed desorption experiments and an evaluation of the effects of Mn promotion on the rate of CO disproportionation. Owing to the appearance of the CO adsorption constant in the numerator and denominator of the rate law, it is possible for promoted catalysts to have both higher and lower turnover frequencies than unpromoted catalysts depending on the chosen operating pressure. As a consequence, an optimal promoter can be found for maximizing the turnover frequency at a given operating pressure. However, product selectivity, which is largely determined by the availability of adsorbed H, is invariably improved by a higher CO adsorption constant because it decreases the ratio of adsorbed H to CO on the Co surface. Strong correlations between catalyst performance and the Lewis acidity of the promoter oxide suggest that Lewis acid-base interactions between the promoter and the adsorbed CO are the cause for the observed metal oxide promotional effects. Much of the experimental data presented in this work favors the hypothesis that CO can interact simultaneously with Co through the C atom and with the promoter cation through the O atom. These chemical interactions, in which the promoter serves as a Lewis acid, weaken the bond between C and O. Experimental evidence for this effect was observed in the lower activation barrier for CO hydrogenation over the ZrO2-promoted catalysts and the appearance of adsorbed carbonyl species on the MnO-promoted catalyst with severely redshifted C-O stretching frequencies measured by in situ infrared spectroscopy. These results provide insight into the chemical mechanism by which metal oxides affect the reaction and identify Lewis acidity of the promoter as the relevant descriptor for quantitatively predicting metal oxide-based promotional effects over Co FTS catalysts.

Download or read book Fischer Tropsch cobalt catalyst improvements with the presence of TiO2 La2O3 and ZrO2 on an alumina support written by Jennifer Lindsey Suder Klettlinger and published by . This book was released on 2012 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Silica Supported Iron cobalt Catalysts for Fischer Tropsch Synthesis written by Robert Merrill Stanfield and published by . This book was released on 1981 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nano carbon Supported Cobalt Catalysts in Fischer Tropsch Synthesis written by Amadeus Rose and published by . This book was released on 2013 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fischer Tropsch Synthesis from Syngas Models Over Cobalt and Copper Zinc Supported Catalysts written by and published by . This book was released on 2009 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sol gel Synthesized Cerium Promoted TiO2 as Cobalt Catalyst Support for Fischer tropsch Synthesis written by Anwaraporn Niltharach and published by . This book was released on 2011 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fischer Tropsch Synthesis Studies On Titania Supported Cobalt Catalyst written by Mohammad Aslam and published by . This book was released on 2017-01-14 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studying the Fischer Tropsch Synthesis on Alumina Support Cobalt Base Catalyst in Fixed Bed Reactor written by Adnan Khalil Oues and published by . This book was released on 2013 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Fischer-Tropsch catalyst composed of cobalt supported on alumina was prepared. This catalyst was cobalt/alumina (Co/AL2 O3 ). The physical characterization of the catalyst was conducted using surface area analysis through the BET method, and particle size analysis. Fischer-Tropsch experiments were conducted in a fixed bed reactor. A flow rate of 100sml/min was selected based experimentally. Two temperatures were 330, and 350°C, and three different pressures as follows 145, 217.6, and 290 psig. The results were evaluated and studied based on conversion of hydrogen and carbon monoxide, in addition to selectivity of products.

Download or read book Fischer Tropsch Synthesis Over Cobalt Supported Catalysts written by Sølvi Storsæter and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fischer troposch Synthesis written by Somruedee Klaithong and published by . This book was released on 2011 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Alumina Supported Cobalt Copper Catalysts for Fischer Tropsch Synthesis of Light Hydrocarbons written by Brent K. Bailey and published by . This book was released on 1978 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fischer Tropsch Synthesis Over SiO2 ZnO and MnO Supported Cobalt Catalysts written by Richard Neil Walsh and published by . This book was released on 1998* with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cobalt Nanoparticles for Fischer Tropsch Synthesis written by and published by . This book was released on 2015 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: La present tesis va consistir en el disseny de nous nanocatalitzadors de cobalt per a la reacció de Fischer-Tropsh (FT). Les nano partícules de Cobalt van ser sintetitzades utilitzant diferents metodologies: reducció química utilitzant borohidrur de sodi com agent reductor o, descomposició tèrmica de compostos organometàl·lics tals com Co2(CO)8. Les síntesis van ser realitzades en presència de polímers com agents estabilitzants. Després de la síntesis, les nano partícules de cobalt foren aïllades, caracteritzades (utilitzant TEM, HR-TEM, XRD, XPS, ICP, FTIR, TGA i RAMAN) i provades en la reacció de Fischer-Tropsch en fase aquosa. Amb la finalitat de comparar amb catalitzadors suportats clàssics, les nano partícules de cobalt van ser immobilitzades amb TiO2 i provades en FT utilitzant un reactor de llit fix. En aquest estudi es va observar que l'activitat i la selectivitat de les nanopartícules de cobalt en ambdós sistemes catalítics depenien altament de paràmetres tals com el mètode de síntesis, el polímer estabilitzant i la mida de partícula. Aquestes diferències van ser atribuïdes a variacions en l'estructura i composició de les nano partícules que alhora eren intrínseques de cada paràmetre d'estudi.