Fluidized bed reactor is a kind of typical catalytic reactors in which solid catalysts (frequently with a diameter of 10–300 μm) are fluidized during the reaction. It is capable of handling a larger amount of reactants or catalysts owing to the large reactor size, and the feed flow rate is required to suspend the catalysts.
PERSPECTIVE. Fluidized-bed reactor scale-up: Reaction kinetics required. Paul M. Witt, Daniel A. Hickman. First published: 12 June 2022. https://doi.org/10.1002/aic.17803. Citations: 1. Read the full text. …
This chapter focuses on fluidized bed reactors and provides tools, techniques and strategies for design, technology development, and project execution. In the preliminary …
As shown above, recent studies on fluidized bed reactor analysis using MPPIC solver are increasing. Numerical simulation of a BFB reactor is possible using the basic MPPIC solver, but for the simulation of a CFB reactor, additional models are needed to process the particle size information and the boundary conditions for bed …
The anaerobic fluidized bed reactor (AFBR) showed an excellent performance and attained steady state conditions with COD removal of 90% after 80 days and the substrate utilization rate indicated a linear increase as a function of time during the process.
A fluidized bed is a state of a two-phase mixture of particulate solid material and fluid, which is widely used in many modern technologies for efficient implementation of various physical and chemical processes. Fluidized beds have been used in technological processes such as: cracking and reforming of hydrocarbons (oil), carbonization and ...
Static Bed Height The transition velocity was almost independent of the static bed height, which varied from 0.4 to 1.0 m (Grace and Sun 1990). Similar results were reported by Cai (1989) and Satija and Fan (1985) with (Hmf/Dt) > 2. On the other hand, for a shallow fluidized bed of (Hmf/Dt) < 2 with Group B and D particles, Canada et
Fluidized Bed Reactors Fluidized bed reactors are used extensively in the chemical process indus-tries. The distinguishing feature of a fluidized bed reactor is that the solids bed of catalytic particles is supported by an upward flow of gas. This reactor provides easy loading and removing of catalyst. This is advantageous when the solids bed ...
A fluidized bed reactor is a type of reactor used to study the behavior and products of pyrolysis at different temperatures and residence times. It is suitable for pyrolysis of materials with low thermal conductivity and high viscosity, but it has disadvantages such as increased capital costs and high energy requirements.
Traditionnally high purity silicon for solar and electronic applications has been produced in Siemens decomposers by hydrogen reduction of chlorosilanes [I]. The yield in the Siemens process is poor. The new cheap routes to silane offer an attractive alternative for silicon production via silane pyrolysis. The thermodynamic yield of this process is . …
In this paper, the most influential parameters (numerical and operating parameters) affecting the performance of fluidized bed reactors are studied. The investigated parameters are constitutive and numerical parameters, minimum fluidization velocity, operating pressure, temperature, gas distributor, and particle size distribution …
fluidized-bed reactor Westerink and Westerterp used the simple model of van Deemter (1961) for a system two consecutive or parallel reactions. They used corre- lations presented by van Swaaij and Zuiderweg (1972) to calculate the mass transfer coefficient, and of Werther (1978) to calculate bubble hold-up. ...
A numerical simulation study was carried out to study the combined thermal behavior and hydrodynamics of a pseudo-2D fluidized bed using a computational fluid dynamics–discrete element method (CFD-DEM). To mimic the effect of heterogeneous exothermic reactions, a constant heat source was implemented in the particle energy …
fluidized bed (Fukuoka et al., 1993). Then, the fluidized bed would drive the bulk of the reac tion while the secondary PFR reactor insured completely converted product out. In summary, for carbothermal reduction synthesis, the primary advantages of fluidized bed reactors are the ability to easily move
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 …
A three-dimensional CFD (computational fluid dynamics) steady-state model was established to simulate biomass gasification in a circulating fluidized-bed (CFB) reactor. The standard k–e turbulence model was coupled with the kinetic theory of granular flow to simulate the hydrodynamics in the gasifier. The kinetics of homogeneous and …
DOI: 10.1016/j.compchemeng.2024.108588 Corpus ID: 267011875; A reinforcement learning-based temperature control of fluidized bed reactor in gas-phase polyethylene process @article{Hong2024ARL, title={A reinforcement learning-based temperature control of fluidized bed reactor in gas-phase polyethylene process}, …
TY - THES. T1 - CFD modeling of biomass combustion and gasification in fluidized bed reactors. AU - Yang, Miao. N1 - Defence details Date: 2023-03-31 Time: 10:00 Place: Lecture hall KC:A, Kemicentrum, Naturvetarvägen 14, Faculty of Engineering LTH, Lund University, Lund External reviewer(s) Name: Halter, Fabien Title: Prof. Affiliation: …
Numerous processes of refining and petro chemistry involve multiphase fluids at extreme conditions, and are realized in agitated reactors or in fluidized beds. The use of high temperature and/or high pressure during conversion and handling of high viscosity materials and/or viscosity ratios results in extreme processing conditions for which the …
The industrial deployment of the fluidized bed reactors (FBR) have recently increased because of their excellent heat and mass transfer characteristics and product efficiency. In the state- of-the art design of these reactors, computational fluid dynamics (CFD) is a recently developed tool which can assist in their scale up. This book describes practical …
Fluidized Bed Reactor Applications. The fluidized bed reactor is used in a wide variety of applications in industry. Some of the main application areas include: 1. Chemical reactions: Fluidized bed reactor is used to carry out chemical reactions such as chemical synthesis, thermal decomposition, catalytic reforming and hydrogenation.
A fluidized sand bed reactor was used to study the production of gases from polyethylene (HDPE) at five nominal temperatures (ranging from 500 to 900°C). Both HDPE primary decomposition and wax cracking reactions take place inside the reactor. Yields of 13 pyrolysis products (methane, ethane, ethylene, propane, propylene, acetylene, …
Fluidized bed reactor is a promising reactor concept because it can handle very exothermal reactions like OCM under isothermal conditions and at the same time it has the potential to recirculate and reactivate the deactivated catalyst in continuous manner. Operation of a fluidized bed reactor has been investigated using complex CFD …
This study presents CFD hydrodynamic simulations of Geldart A group particles in a fluidized bed using two different types of particles. The simulation was performed using Comsol Multiphysics for multiphase flow, in a 2 dimensional (2-D) configuration. The Eulerian-Eulerian approach was used to simulate the hydrodynamic …
This review aims to overview the process modeling of CLC in fluidized bed reactors, focusing on the macroscopic modeling approach and the use of semiempirical correlations to describe the relevant bubbling and …
The modeling of biomass gasification processes by simulators such as Aspen Plus is a powerful tool to assess mass and energy balances and to optimize process designs. A detailed model of the gasification reactor is one of the key points to achieve an accurate process description. A model for biomass gasification in dual fluidized bed …
A fluidized bed is a physical phenomenon occurring when a quantity of a solid particulate substance (usually present in a holding vessel) is placed under appropriate conditions to cause a solid/fluid mixture to behave as a fluid.This is usually achieved by the introduction of pressurized fluid through the particulate medium. This results in the …
Such a catalyst, t; _ Pl QspA, BFI 4 1 - YXcao,a- I 2 (16) Fuel 1998 Volume 77 Number 4 331 Circulating fluidized bed reactors: R. Soutdeh-Gharebaagh et al. Table 1 The reactor models description utilized in the simulation' 5, 16 Reactor block RYIELD RSTOIC RCSTR REQUIL Description To simulate a reactor by speciying yield …
The fluidized bed reactor process is not without its challenges. With graphite reactors, heating is limited to the walls, which limits scale-up due to heat transfer challenges from the decreased surface to reactor volume ratio of larger units. Fines build-up in the freeboard region can also be a problem.
In this chapter the characteristics of fluidized gas–solid suspensions are described, and the basic designs of fluidized bed reactors are sketched. Several modeling approaches that have been applied to described these units are outlined.