In threephase fluidized beds the particles are supported by the liquid andor the gas while in slurry reactors the solid particles are suspended by the momentum. In a three phase fluidization the particulate solid is suspended in an upward cocurrent flow of gas and liquid. Computer aided design and analysis of three phase fluidized bed biofilm reactors for waste water treatment article pdf available june 2015 with 89 reads how we measure reads. Tio2 powder was employed as the photocatalysts and a 15 w low pressure mercury lamp was used as the. Yalova, istanbul textile plant has been examined in a three phase fluidized bed reactor at different conditions. Microbial removal of ionic mercury in a threephase. Pdf performance of a threephase fluidized bed reactor with.
Model equations for a bubbling fluidized bed reactor can be developed by writing material balance equations of each of the three phases inside the reactor. Bed plugging and channelling can be reduced due to the movement of solids. Hydrodynamic characterization and performance evaluation. Behaviour of three phase fluidized bed with regular. In this type of reactor, a fluid gas or liquid is passed through a solid granular material usually a catalyst possibly shaped as tiny spheres at high enough velocities to suspend the solid and cause it to behave as though it were a fluid. Slurry reactors are most frequently used when a liquid reactant must be contacted with a solid catalyst, and when a reaction has a high heat of reaction. Modeling of ethanol bioproduction in threephase fluidized. Some of the advantages of three phase fluidized bed reactor. The performance of a threephase fluidized bed reactor in treatment of wastewater with high organic load. A three phase fluidized bed anaerobic biofilm reactor model for treating complex substrates mauren fuentesa, miguel c. Pdf minimum fluidization velocity in a three phase. Pdf microbial removal of ionic mercury in a threephase.
Behaviour of three phase fluidized bed with regular particles. Three phase fluidized beds also commonly referred to as gasliquidsolid fluidized beds. Dfcontaminated water from a 200 l feed tank enters at the bottom of the reactor along with an air stream. Cfd analysis of phase holdup behaviour in a three phase. Consequently, a detailed design of a fluidized bed reactor that would allow flexible operation at high temperature and high pressure at several gas velocities will be conducted in order to serve for the future development of new hydrodynamic models. Today, about three quarters of all polyolefins are made by a fluidized bed process. Liquidphase volumetric mass transfer coefficients, kla were determined in threephase inverse fluidized bed reactor of polypropylene pp spheres with 8mm diameter, fluidized by a countercurrent. Pharmaceutical and biological waste treatment sectors. In slurries, the catalyst is suspended in a liquid, whereas in fluidized beds, the suspending fluid is the reacting gas itself.
Volume of catalyst in the bubbles, clouds, and emulsion. Biodegradation of diesel fuelcontaminated wastewater. Some hydrodynamic characteristics of inverse three phase fluidized. Optimization of fluidized bed carbochlorination of. Photocatalytic oxidation of methyl orange in a three phase fluidized bed reactor. Pdf modeling of ethanol bioproduction in threephase fluidized. To accomplish this task several experiments were performed covering a wide range of yeast and glucose concentrations, reaction temperatures, and liquid and gas velocities. Three phase fluidization the threephase fluidized bed is a type of system that can be used to carry out variety of multiphase chemical reactions.
University of groningen particle transport in fluidized. An improved version of a pilot fluidized bed reactor with the production capacity of 10 kg per day was designed and built. They may be used in such applications as hydrogenation, oxidation, hydroformation, and ethynylation. Two different recycling and aeration flow rates were used in the experiments. Development of a threephase fluidized bed reactor with. Slurry reactors are similar to fluidized bed reactors in that a gas is passed through a reactor containing solid catalyst particles suspended in a fluid. Fluidized bed reactor an overview sciencedirect topics.
Pdf computer aided design and analysis of three phase. Microbial removal of ionic mercury in a threephase fluidized bed reactor. Prediction of minimum fluidization velocity in threephase. Comparing immobilized cellulase activity in a magnetic. Moving particles, especially small particles, can transport heat much more efficiently than gas alone.
Fluidization principles for threephase fluidized bed bio. The development of a specialized zeolite catalyst for cracking heavy oil into various fractions enabled the commercialization of the fcc circulating fluidized bed. A flow diagram of the gas phase fluidized bed polypropylene production process is shown in figure 1. Wavelet transform analysis of pressure fluctuation signals.
For simplicity, a first order reaction is assumed in the following derivation. The advantages of fluid bed bioreactors fbbr are mainly food. Modeling of ethanol bioproduction in threephase fluidized bed reactors. Pdf photocatalytic oxidation of methyl orange in a three.
Behaviour of three phase fluidized bed with irregular. A threephase fluidized bed anaerobic biofilm reactor. The tpfb is used, first, to carry out the biotransformation. Pdf kinetic model for dynamic response of threephase.
These are three phase fixed and fluidized bed reactors, three phase semi fluidized beds, slurry bubble columns and. A novel, magnetic three phase fluidized bed reactor mtfbr was designed with magnetic immobilized cellulase mic as the biocatalyst for preparing chitooligosaccharides from chitosan. In order to optimize the operating conditions of the reactor, the fluidized bed zirconia carbochlorination reactor was modeled via a two phase hydrodynamic model. The threephase condition and the smaller effective size of the supporting media of the aafbr that increases the bed specific surface area contributed to improve the absorption capacity of the carrier. The effects of inlet chemical oxygen demand concentration cod in, ph, different catalyst types perflorooctyl alumina pfoa and alumina and catalyst dosage on. Circulating operation can promote solids mixing and increase product throughput per unit bed cross section, while high shear stress can promote biofilm renewal pirozzi et al. Prediction of minimum fluidization velocity in three phase fluidized bed reactors fa. A threephase fluidized bed reactor tfbr was developed in this study with the objective to achieve high rates of oxygen transfer from the gas to the liquid phase in the presence of fluidized. Fluidization principles for threephase fluidized bed bioreactor. Scribd is the worlds largest social reading and publishing site. The cod removal efficiency obtained in the aafbr was much higher than the reported by ng et al.
Energy dissipation rate and pressure fluctuations in a three phase fluidized bed with a large column diameter 1067 korean j. Pressure drop is less due to which pumping cost can be reduced etc. We proposed the wavelet transform as a new alternative tool for identification of bed properties in three phase fluidized bed reactor. Slurry visual encyclopedia of chemical engineering. The liquid forms a continuous phase and the gas is a dispersed bubble phase. Heat and mass transfer in threephase fluidizedbed reactorsan. Ethanol bioproduction in threephase fluidized bioreactors. In a three phase fbbr, bed of solids is fluidized by the cocurrent flow of a liquid and a gas. The mic showed higher enzyme activity in a pulse magnetic field pmf than that in a steady magnetic field smf or alternating magnetic field amf under certain operating parameters.
The performance of a threephase fluidized bed reactor in treatment. The heattransfer rate in a fluidized bed can be five to ten times greater than that in a packedbed reactor. The solid particles were supported on a perforated stainless steel plate with 786 evenly spaced holes. Modelbased optimal reactor choice is based on the minimum amount. Three phase reactor can be classified into two types of reactor depending on its density and volume fraction of particles. Pdf the aerobic treatment of dairy wastewater was performed experimentally in a three phase fluidizedbed bioreactor fbbr using culture. The setup comprises a cylindrical three phase fluidized bed reactor of 3 m height, and 17 cm internal diameter. The reductive biotransformation of mercuric ions to elemental mercury was studied by applying a model system with a genetically engineered pseudomonas putida strain in a lab scale three phase fluidized bed tpfb. The effects of gas and liquid velocities, solid and liquid properties on the heat and mass transfer coefficients in threephase fluidized beds have been determined.
The reactor shown below is a slurry phase hydrogenation reactor. Article pdf available in chemical engineering communications 791. Modeling and simulation of gasliquid interfacial area in. Knowledge of the onset of fluidization is of considerable relevance and the key to three phase fluidized bed reactors design and safe operation. The number of pvc support particles used comprised 0. Energy dissipation rate and pressure fluctuations in a.
The performance of a threephase fluidized bed reactor 221 fed in during a period of three days until reaching 18 lh. A correlation for the liquid holdup and bed porosity could be. Accordingly, using a wide historic u lmf database set up from the open literature, all the quantification methods proposed to predict the minimum fluidization liquid velocity in three phase fluidized. Even for the most extreme exothermic reactions, a fluidized bed can maintain an isothermal profile within a few degrees.
A threephase fluidized bed reactor tfbr was developed in this study with the objective to achieve high rates of oxygen transfer from the gas to the liquid phase in the presence of fluidized solid particles. Kinetic model for dynamic response of three phase fluidized bed biofilm reactor for wastewater treatment. Of late more interest has been taken in three phase mode of operation. Epstein 3 distinguished in particular the difference between three phase fluidized beds and slurry reactors. Theoretical in this section, only a brief introduction to fourier transform and wavelet transform is provided. In this model, in each stage, the bubble phase is considered as a pfr reactor and the emulsion phase is considered as a cstr.
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