Download or read book KINETIC MODELING OF A FISCHER TROPSCH REACTION OVER A COBALT CATALYST IN A SLURRY BUBBLE COLUMN REACTOR FOR INCORPORATION INTO A COMPUTATIONAL MULTIPHASE FLUID DYNAMICS MODEL written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently multi-tubular fixed bed reactors, fluidized bed reactors, and slurry bubble column reactors (SBCRs) are used in commercial Fischer Tropsch (FT) synthesis. There are a number of advantages of the SBCR compared to fixed and fluidized bed reactors. The main advantage of the SBCR is that temperature control and heat recovery are more easily achieved. The SBCR is a multiphase chemical reactor where a synthesis gas, comprised mainly of H2 and CO, is bubbled through a liquid hydrocarbon wax containing solid catalyst particles to produce specialty chemicals, lubricants, or fuels. The FT synthesis reaction is the polymerization of methylene groups [-(CH2)-] forming mainly linear alkanes and alkenes, ranging from methane to high molecular weight waxes. The Idaho National Laboratory is developing a computational multiphase fluid dynamics (CMFD) model of the FT process in a SBCR. This paper discusses the incorporation of absorption and reaction kinetics into the current hydrodynamic model. A phased approach for incorporation of the reaction kinetics into a CMFD model is presented here. Initially, a simple kinetic model is coupled to the hydrodynamic model, with increasing levels of complexity added in stages. The first phase of the model includes incorporation of the absorption of gas species from both large and small bubbles into the bulk liquid phase. The driving force for the gas across the gas liquid interface into the bulk liquid is dependent upon the interfacial gas concentration in both small and large bubbles. However, because it is difficult to measure the concentration at the gas-liquid interface, coefficients for convective mass transfer have been developed for the overall driving force between the bulk concentrations in the gas and liquid phases. It is assumed that there are no temperature effects from mass transfer of the gas phases to the bulk liquid phase, since there are only small amounts of dissolved gas in the liquid phase. The product from the incorporation of absorption is the steady state concentration profile of the absorbed gas species in the bulk liquid phase. The second phase of the model incorporates a simplified macrokinetic model to the mass balance equation in the CMFD code. Initially, the model assumes that the catalyst particles are sufficiently small such that external and internal mass and heat transfer are not rate limiting. The model is developed utilizing the macrokinetic rate expression developed by Yates and Satterfield (1991). Initially, the model assumes that the only species formed other than water in the FT reaction is C27H56. Change in moles of the reacting species and the resulting temperature of the catalyst and fluid phases is solved simultaneously. The macrokinetic model is solved in conjunction with the species transport equations in a separate module which is incorporated into the CMFD code.
Download or read book Development of a Computational Multiphase Flow Model for Fischer Tropsch Synthesis in a Slurry Bubble Column Reactor written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The model includes heat generation due to the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. Results of the CMFD simulations (similar to those shown in Figure 1) will be presented.
Download or read book Progress Towards Modeling of Fischer Tropsch Synthesis in a Slurry Bubble Column Reactor written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The model includes heat generation due to the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. Results of the CMFD simulations (similar to those shown in Figure 1) will be presented.
Download or read book Incorporation of Reaction Kinetics Into a Multiphase Hydrodynamic Model of a Fischer Tropsch Slurry Bubble Column Reactor written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different industrial processes and reactor geometries. The NPHASE CMFD solver [1] is used as the robust computational platform. Results from the CMFD model include gas distribution, species concentration profiles, and local temperatures within the SBCR. This type of model can provide valuable information for process design, operations and troubleshooting of FT plants. An ensemble-averaged, turbulent, multi-fluid solution algorithm for the multiphase, reacting flow with heat transfer was employed. Mechanistic models applicable to churn turbulent flow have been developed to provide a fundamentally based closure set for the equations. In this four-field model formulation, two of the fields are used to track the gas phase (i.e., small spherical and large slug/cap bubbles), and the other two fields are used for the liquid and catalyst particles. Reaction kinetics for a cobalt catalyst is based upon values reported in the published literature. An initial, reaction kinetics model has been developed and exercised to demonstrate viability of the overall solution scheme. The model will continue to be developed with improved physics added in stages.
Download or read book Catalysis for Clean Energy and Environmental Sustainability written by K. K. Pant and published by Springer Nature. This book was released on 2021-04-01 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is part of a two-volume work that offers a unique blend of information on realistic evaluations of catalyst-based synthesis processes using green chemistry principles and the environmental sustainability applications of such processes for biomass conversion, refining, and petrochemical production. The volumes provide a comprehensive resource of state-of-the-art technologies and green chemistry methodologies from researchers, academics, and chemical and manufacturing industrial scientists. The work will be of interest to professors, researchers, and practitioners in clean energy catalysis, green chemistry, chemical engineering and manufacturing, and environmental sustainability. This volume focuses on catalyst synthesis and green chemistry applications for petrochemical and refining processes. While most books on the subject focus on catalyst use for conventional crude, fuel-oriented refineries, this book emphasizes recent transitions to petrochemical refineries with the goal of evaluating how green chemistry applications can produce clean energy through petrochemical industrial means. The majority of the chapters are contributed by industrial researchers and technicians and address various petrochemical processes, including hydrotreating, hydrocracking, flue gas treatment and isomerization catalysts.
Download or read book Design of Multiphase Reactors written by Vishwas G. Pangarkar and published by John Wiley & Sons. This book was released on 2015-01-27 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Details simple design methods for multiphase reactors in the chemical process industries Includes basic aspects of transport in multiphase reactors and the importance of relatively reliable and simple procedures for predicting mass transfer parameters Details of design and scale up aspects of several important types of multiphase reactors Examples illustrated through design methodologies presenting different reactors for reactions that are industrially important Includes simple spreadsheet packages rather than complex algorithms / programs or computational aid
Download or read book Effect of Operating Variables Upon the Fischer Tropsch Synthesis written by Sol W. Weller and published by . This book was released on 1949 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bubble Column Reactions written by Wolf-Dieter Deckwer and published by John Wiley & Sons. This book was released on 1992-04-08 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: This technology, though used for many years, has shown great vitality recently and is still in a state of flux. Provides an account of developments up to the present and also an orderly evaluation of literature already published on the subject. Considerable space is devoted to bubble column reactor performance predictions based on mathematical models and the importance of each is explained with practical examples.
Download or read book Fischer Tropsch Synthesis Catalysts and Catalysis written by Burtron H. Davis and published by CRC Press. This book was released on 2016-04-06 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on a symposium held during the 248th American Chemical Society meeting that focused on use of the Fischer-Tropsch process in producing synthetic fuels. Its contents reflect the four dominant subjects of the meeting: catalyst preparation and activation, catalyst activity and reaction mechanisms, catalyst characterization and related reactions, and topics concerning commercializing the Fischer-Tropsch process. It covers recent developments related to renewable resources and green energy and provides a glimpse of the commercial potential of the Fischer-Tropsch process in synthetic fuel production.
Download or read book Slurry Phase Fischer Tropsch Synthesis written by and published by . This book was released on 1989 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rate of synthesis gas consumption over a cobalt FischerTropsch catalyst was measured in a well-mixed, continuous-flow, slurry reactor at 220 to 240°C, 0.5 to 1.5 MPa, H2/CO feed ratios of 1.5 to 3.5 and conversions of 7 to 68% of hydrogen and 11 to 73% of carbon monoxide. The inhibiting effect of carbon monoxide was determined quantitatively and a Langmuir-Hinshelwood-type equation of the following form was found to best represent the results: -R{sub H{sub 2+Co}} = (a P{sub CO}P{sub H{sub 2}})/(1 + b P{sub CO})2. The apparent activation energy was 93 to 95 kJ/mol. Data from previous studies on cobalt-based Fischer-Tropsch catalysts are also well correlated with this rate expression.
Download or read book Multiphase Flow Analysis Using Population Balance Modeling written by Guan Heng Yeoh and published by Butterworth-Heinemann. This book was released on 2013-08-19 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by leading multiphase flow and CFD experts, this book enables engineers and researchers to understand the use of PBM and CFD frameworks. Population balance approaches can now be used in conjunction with CFD, effectively driving more efficient and effective multiphase flow processes. Engineers familiar with standard CFD software, including ANSYS-CFX and ANSYS–Fluent, will be able to use the tools and approaches presented in this book in the effective research, modeling and control of multiphase flow problems. - Builds a complete understanding of the theory behind the application of population balance models and an appreciation of the scale-up of computational fluid dynamics (CFD) and population balance modeling (PBM) to a variety of engineering and industry applications in chemical, pharmaceutical, energy and petrochemical sectors - The tools in this book provide the opportunity to incorporate more accurate models in the design of chemical and particulate based multiphase processes - Enables readers to translate theory to practical use with CFD software
Download or read book Fischer Tropsch Process on Cobalt containing Unsupported Catalysts in Slurry Reactor written by A. A. Khassin and published by . This book was released on 1997 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Slurry Phase Fischer Tropsch Synthesis written by and published by . This book was released on 1990 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments on cobalt-catalyzed reactions of light 1-alkenes added to synthesis gas were performed. Data have been collected at 220C, 0.45 to 1.48 MPa and a synthesis gas flow rate between 0.015 and 0.030 Nl/(gcat·min) with H2/CO of 1.45 to 2.25. Ethylene, propene, and butene were added to synthesis gas feed from 0.5 to 1.2 mole% of total feed. For each material balance in which 1-alkenes were added, a material balance was performed at similar process conditions without 1-alkenes added, as ''base case''. Material balances without added 1-alkenes were also repeated to verify of catalyst selectivity stability. 49 material balances were performed during a single run lasting over 2,500 hours-on-stream. The hydrocarbon data have been completely analyzed; data correlations are still being made. Since C3/C1 ratios by ethene addition, C4/C1 ratios by propene addition, and C5/C1 ratios by 1-butene addition, it appears that 1-alkenes may incorporate into growing chains on the surface of the catalyst. Further evidence for incorporation can be seen by comparing selectivity to n-alcohol one carbon number higher than added 1-alkene. Yield of this n-alcohol increases when alkenes are present. Sensitivity of hydrocarbon distribution to process variables seems to be greater on Co than on Fe catalysts.
Download or read book Three phase Catalytic Reactors written by P. A. Ramachandran and published by Gordon & Breach Publishing Group. This book was released on 1983 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluidized Bed Reactors Processes and Operating Conditions written by John G. Yates and published by Springer. This book was released on 2016-09-27 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.
Download or read book Fischer Tropsch Technology written by André Steynberg and published by Elsevier. This book was released on 2004-10-30 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fischer-Tropsch Technology is a unique book for its state-of-the-art approach to Fischer Tropsch (FT) technology. This book provides an explanation of the basic principles and terminology that are required to understand the application of FT technology. It also contains comprehensive references to patents and previous publications. As the first publication to focus on theory and application, it is a contemporary reference source for students studying chemistry and chemical engineering. Researchers and engineers active in the development of FT technology will also find this book an invaluable source of information. * Is the first publication to cover the theory and application for modern Fischer Tropsch technology * Contains comprehensive knowledge on all aspects relevant to the application of Fischer Tropsch technology* No other publication looks at past, present and future applications
Download or read book Slurry Phase Fischer Tropsch Synthesis written by and published by . This book was released on 1990 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Co/MgO/SiO2 Fischer-Tropsch catalyst was operated simultaneously with a Cu/ZnO/Al2O3 water-gas-shift catalyst in a slurry reactor for over 400 hours. The process conditions were held constant at a temperature of 240°C, a pressure of 0.79 MPa, and a 1.1 H2/CO feed of 0.065 Nl/min-g.cat. The Fischer-Tropsch activity remained constant at the level predicted by the operation of the Co/MgO/SiO2 catalyst alone. The water-gas-shift reaction was near equilibrium. The hydrocarbon product distribution of the combined catalyst system was stable and matched that of the CO/MgO/SiO2 operating alone under similar conditions. The combined catalyst system exhibited a high selectivity to n-alkanes. Neither catalysts's operation appeared to have a detrimental effect on that of the other, showing promise for future option.
