Progress in CFD Simulations of Fluidized Beds for
Gas-solid fluidized beds have drawn the attention of engineers and researchers as an effective technology for a large variety of applications, and num…
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(PDF) Modeling the catalytic oxidation of n-butane to maleic …
The gas-phase catalytic oxidation of benzene was carried out in laboratory-scale fluidized-bed and fixed-bed reactors with a vanadium pentoxide catalyst supported by silica gel. The influences of parameters such as temperature, space time, and air-to-benzene molar ratio on the reaction selectivity were investigated at normal atmospheric pressure.
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Fluidized-Bed Reactors
Fluidized-bed processes for heterogeneous catalytic gas-phase reactions, for the polymerization of olefins, for homogenous gas-phase reactions, gas–solid reactions and applications in biotechnology are described in detail. A final chapter is devoted to the modeling of fluidized-bed reactors.
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Power-to-gas: CO2 methanation in a catalytic fluidized bed reactor …
Experiments were performed in a demonstration scale catalytic methanation reactor on the GAYA demonstration plant located at Saint-Fons, France (Fig. 1).The reactor consists in a fluidized bed reactor (total length of 5.4 m) composed of a fluidizing volume (internal diameter of 0.30 m) and a disengagement zone (internal diameter of …
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First Commercial Fluid Bed Reactor
The first commercial circulating fluid bed reactor, PCLA #1 (Powdered Catalyst Louisiana), went on stream on May 25, 1942, in the Baton Rouge Refinery of the Standard Oil Company of New Jersey (now ExxonMobil Corporation). ... The creation and development of the fluidized bed reactor system for catalytic cracking of petroleum was a cooperative ...
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Circulating Fluidized Beds for Catalytic Reactors
A circulating fluidized bed (CFB) system is therefore ideal for the design of the large-scale reactors needed for the economic production of fuels and large-volume chemicals. Catalytic reactions and reaction models for combustion and gasification systems are discussed. Computational fluid dynamics (CFD) simulations for a CFB gasification ...
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Fluidized bed catalytic reactor modeling across the flow …
Fluidized bed reactor models are generally specific to a single flow regime resulting in ambiguities and discontinuities at the regime boundaries. In practice, only the bubbling, turbulent and fast fluidization regimes are …
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Review of catalytic reforming for hydrogen production in a …
Catalytic reforming technology is regarded as one of the most popular hydrogen production methods. The introduction of a fluidized bed reactor provides a promising opportunity for the enhancement of catalytic reforming technology owing to its good gas-solid contact as well as heat and mass transfer characteristics.
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Dehydrogenations in fluidized bed: Catalysis and reactor engineering
FBD reactor–regenerator cycle. The dehydrogenation reaction is carried out in a catalytic bubbling fluidized bed operating above 500 °C and slightly above atmospheric pressure. The catalyst circulates (like a …
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Modified mathematical model for gas phase olefin …
In the fluidized-bed system considered here as seen in Fig. 1, the reactant gas enters the bottom of the bed and flows up the reactor in the form of bubbles.As the bubbles rise, mass transfer of the reactant gases takes place between the bubbles and the clouds and between the clouds and the emulsion without chemical reaction.
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A review on modeling and control of olefin polymerization in fluidized
1 Introduction. Olefin polymerization in gas-phase fluidized-bed reactors (FBRs) is known to be one of the most economic methods of manufacturing commodity polymers including polyethylene (PE), polypropylene (PP) and ethylene-propylene rubber (EPR). FBRs are extensively used in operations that involve solid catalysts.
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Fluidized-bed catalytic reactors
Summary. Fluidized-bed reactors are used for solid-catalyzed reactions when their desirable features (favorable heat transfer, temperature uniformity, high effectiveness factors, low pressure drop, and ability to add/remove catalyst) outweigh …
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Fluidized Bed Reactor | 18 | Particle Technology and …
The advantages of gas-solid-˜uidized bed reactors relative to packed bed reactors are: • Greatly improved bed-to-wall and bed-to-immersed-surface heat transfer • Reduced axial and lateral temperature gradients, minimizing the probability of. hot spots, catalyst sintering, and unwanted side reactions • Ability to add or remove particles ...
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100 years of scaling up fluidized bed and circulating …
Abstract. This year, 2022, we celebrate the 100-year anniversary of the commercialization of the fluidized bed reactor. In those years, many new processes …
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Fluidized Bed Reactor
Fluidized bed reactors are another class of multiphase catalytic reactors which have unique advantages in terms of heat and mass rates and mixing. In two- or three-phase …
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CHAPTER 7: Fixed-Bed Catalytic ReactorsI
7/161. Catalyst Properties. The following shapes are frequently used in applications: 20–100 µm diameter spheres for fluidized-bed reactors 0.3–0.7 cm diameter spheres for fixed-bed reactors 0.3–1.3 cm diameter cylinders with a length-to-diameter ratio of 3–4 up to 2.5 cm diameter hollow cylinders or rings.
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100 years of scaling up fluidized bed and circulating fluidized bed …
The high heat of reaction was managed using a fluidized bed reactor as temperature control was critical to managing thermal decomposition, which compromises product yields. In 1960, a commercial Sohio process was born. Today, 90% of all commercial acrylonitrile production use fluidized bed reactors based on the Sohio …
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Fluidized Bed (FBR) – Visual Encyclopedia of Chemical …
See more on encyclopedia.che.engin.umich.edu
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What is the difference between fixed bed and fluidized bed?studybuffFluidized Bed ReactorWebDiameter-transformed fluidized beds (DTFBs) possess unique advantages in terms of their ability to control complex catalytic reactions. The design and scale-up of …
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Fundamentals of Reactor Design and Scale-Up | SpringerLink
Compared to traditional reactors, such as multilayer and multichamber fluidized beds, DTFBs allow multiple flow regimes to coexist in a single reactor with continuous control of reactions. Thus, DTFBs have been widely used for processes with complex catalytic reactions; e.g., fluid catalytic cracking (FCC), reaction of FCC residue, …
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Introduction to Fluidization
Winkler coal gasifier in Germany. Fluidized catalytic cracking units (FCCUs) for the production of high-octane gasoline and fluidized-bed reactors for making phthalic anhydride debuted in the 1940s. Today, about three-quarters of all polyolefins are made by a fluidized-bed process. The development of a specialized zeolite catalyst for
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Elements of Chemical Reaction Engineering
For the catalytic cracking of petroleum naphthas to form gasoline blends, as an example, the virtues of the fluidized-bed reactor drove its competitors from the market. Fluidization occurs when small solid particles are suspended in an upward-flowing stream of fluid, as shown in Figure CD12-2.
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Reactors – Visual Encyclopedia of Chemical Engineering …
Trickle bed reactors are solid-liquid-gas contacting devices wherein a liquid stream flows downward over a bed of catalyst with pressure difference serving as the driving force . The fluid flows over catalyst particles and forms fine films, rivulets or droplets. The gas stream can either flow concurrent with the liquid or countercurrent to it ...
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Performance Enhancement of Fluidized Bed Catalytic …
Fluidization is an important operation for multiphase reactions, especially for gas-phase catalytic reactions because it provides a large solid surface area for improved …
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Circulating Fluidized Beds for Catalytic Reactors | SpringerLink
A circulating fluidized bed (CFB) system is therefore ideal for the design of the large-scale reactors needed for the economic production of fuels and large-volume …
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Fluidized Bed Reactor
Fluidized-bed reactors are theoretically an excellent reactor type choice for highly exothermic reactions, such as the FT reaction. Fluidized-bed reactors offer a much …
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INTRODUCTION TO FLUIDIZED BEDS
Fast Fluidized Bed. The fast fluidization occurs as a result of continuing increasing in operating velocity beyond that required at turbulent fluidization, a critical velocity, commonly called the transport velocity (Utr), will be reached where a …
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Fluidized Bed Reactor
In a dual fluidized bed (DFB) reactor, the energy for steam gasification of solid biomass at temperatures of typically 850–900 °C is supplied by a hot bed material (e.g., olivine), which circulates between two fluidized bed reactors, namely, a gasifier and a combustor.Biomass residuals (char) from the gasification step and the bed material are transported to the …
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Packed Bed (PBR)
General Information. Packed bed reactors consist of a cylindrical shell with convex heads. Most are vertical and allow reactants to flow by gravity. Inside the reactor is an immobilized, or fixed, bed of catalyst. Packed bed reactors are heterogeneous reaction systems. The picture below shows an apparatus used to study flow through a packed column.
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Circulating fluidized bed as a catalytic reactor: …
In recent years, the circulating fluidized bed as a reactor has experienced increasing application in industry. A circulating fluidized bed (CFB) has some unique features as a chemical reactor. The performance of the CEB reactor was investigated in a O.25-m-dia. Riser system with ozone decomposition in the reactor.
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Multiple isolas in steady‐state characteristics of fluidized bed
Steady-state characteristics of a catalytic fluidized bed reactor are analyzed. A two-phase bubbling model is used for the description of a fluidized bed of a catalyst. Particular attention is focused on the theoretical and technological consequences of a newly observed steady-state behavior. Features of the model are presented in terms …
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