Hydrodesulfurization of vacuum gas oil in a trickle bed reactor was. Trickle bed reactor, drag coefficient, computational fluid dynamics cfd, ergun equation, pellet scale model introduction multiphase flow systems, in which gas and liquid flow concurrently downward through a packed bed, are extensively applied in processing of fuels and chemicals such as desulfurization, hydro. Such complex interactions manifest in different flow regimes occurring in trickle bed reactors. By using computational fluid dynamics cfd, we can understand fluid dynamics and its interactions with chemical reactions. Cfd prediction of hydrodynamics in highpressure trickle. Kinetic interpretation and optimal operating conditions of. Based on previous work focused on threephase tricklebed reaction 2, the electrical capacitance tomography ect is pondered in this work as a plausible nonintrusive method of investigation for the deposition mechanisms and.
The simulation results show a good agreement with the. Publishers pdf, also known as version of record includes final. The schematic diagram of the setup is shown in fig. To improve the capability of multiphase reactor models, one has to solve the complete multidimensional flow equations coupled with chemical species transport, reaction kinetics, and kinetics of phase change. But hydrodynamics of trickle bed reactor involve complex interaction of gas and liquid phase with packed solid which is very difficult to understand. In addition, the hyrodesulfurication of a hydrocarbon in a trickle bed reactor is given in detail by tarhan 7.
In this work, three different aspects in design of tbr have been addressed using cfd simulations. Key technological aspects of trickle bed reactor and some examples of industrial trickle bed processes are discussed in chapter 1. This section gives the comprehensive manual for obtaining crosssectional phase. Other workedout trickle bed example problems can be found in an article by ramachandran and chaudhari 6. Pro ii, process simulation package was used to predict vaporization and gas and liquid properties of the phases at the reaction conditions. Numerical model for trickle bed reactor 3 implementation of the sequential algorithm. Hydrodynamics of trickle bed reactors open scholarship. Introduction the term trickle bed is used here to mean a reactor in which a liquid phase and a gas phase flow concurrently downward through a fixed bed of catalyst particles while reaction takes place.
However, if the tricklebed reactor were to be run in countercurrent. Finally, a comparison between the two measuring techniques shows the limitations of the liquid collector and the improper conclusions to which its use could lead. Pdf the properties of diluted catalyst beds made by different packet methods were compared to determine the hydrodynamic characteristics and peclet. Cfd modeling of trickle bed reactors outline trickle bed reactors applications flow regimes experiments cfd modeling of trickle bed reactors interphase momentum exchange capillary terms estimation of fraction of liquid suspended in gas phase simulating hydroprocessing reactor reaction kinetics other submodels.
Catalytic bed grid generation for the trickle bed reactor was created using the integrated solid modeling and meshing program gambit fluent inc. It is considered to be the simplest reactor type for performing catalytic reactions where a gas and liquid normally both reagents are present in. Liquid spreading in a trickle bed reactor is characterized through liquid holdup and pressure drop measurements for different particle sizes, and liquid and gas flow rates. When products inhibit the reaction, the countercurrent operation is expected to have an advantage over the cocurrent operation. Trickle bed reactors are widely used for heterogeneously catalyzed reactions in liquid and solid phase or gas phase reaction on solid catalysts particle in inert. Pdf hydrodynamics characteristics of hds trickle bed test reactor. Knowledge of prevailing flow regime, pressure drop, and liquid holdup is essential for design and performance evaluation of the reactor.
The deep desulfurization of oil fraction is a central matter of concern to every refinery. Apr 05, 2017 for the love of physics walter lewin may 16, 2011 duration. Mohit kumar 2016cl03 hitesh babu 2016cl08 chemical department, mnnit allahabad introduction trickle bed reactor is a reactor in which a liquid and a gas phase flow cocurrently downward on stationary catalyst packing while the reaction takes place. Fixed bed catalytic reactors are widely used in petrochemical and refinery processes for crude oil hydro treating. Biological trickle bed reactor lack of space, purification of waste gases with phrelevant constituents or end products and applications where the sole use of a biofilter is not satisfying, require a different approach. A trickle bed reactor is a continuous, packed bed reactor where the liquid flows down in the direction of gravity through a bed of solid catalyst particles. It is considered to be the simplest reactor type for performing catalytic reactions where a gas and liquid normally both reagents are present in the reactor and accordingly it is extensively used. Hydrodynamics modeling of a commercial scale trickle bed. Functional principle the biological trickle bed reactor has. Simulations were performed for a pilot trickle bed reactor, and the results are discussed in terms of variations with axial position of partial pressure and concentrations in liquid phase. Modelling gasliquid flow in tricle bed reactors katja lappalainen dissertation for the degree of doctor of science in technology to be presented with due permission for public examination and debate in auditorium v1 at helsinki university of technology espoo, finland on the 5th of june, 2009, at 12 noon. We discuss the solution of the pressure equation using a multigridaccelerated iterative method 8 and the saturation equation using. In this study, the hydrodynamic and thermal behavior of trickle bed reactors was simulated by means of computational fluid dynamics cfd technique. The solid particles inside the reactor can be randomly packed or in.
Hydrodynamics and flow regime transition study of trickle bed. Hydrodynamics of trickle bed reactors involve complex interactions of gas and liquid phases with packed solids. Computational fluid dynamics analysis of twophase flow in a. Introduction trickle beds reactors are widely used chemical reactors in which a gas and a liquid flow cocurrently downwards through a fixed bed of solid particles. Majority of reactions carried out in a trickle bed reactor like hydro cracking are exothermic in nature. Cfd simulation of porosity and particle diameter influence on. Hydrocarbon hydrodesulfurization in vertical, inclined and. This paper reports an experimental verification of a nonisothermal trickle bed reactor model for hydro genation of 2,4 dinitrotoluene dnt which repres ents a case of highly exothermic ah 556 kjmol. Pdf computational fluid dynamics modeling of trickle bed reactor.
A tricklebed reactor tbr is a chemical reactor that uses the downward movement of a liquid and the downward cocurrent or upward countercurrent movement of gas over a packed bed of particles. In this masters thesis, a computational trickle bed reactor model by neste jacobs is used in aspen plus to model the performance of a trickle bed reactor, and based on observations a procedure for preliminary design of trickle bed reactor is suggested. Multi bed downflow trickle bed reactors tbrs find enormous applications in petroleum refinery, petrochemicals industry and effluent treatment. For the love of physics walter lewin may 16, 2011 duration. Cfd prediction of hydrodynamics in highpressure trickle bed reactor article pdf available in journal of chemical engineering of japan 42supplement. For example, a large part of the literature data and theoretical developments regarding trickle bed hydrodynamics is based on cold mockups involving for example air and water without any reaction. Estimation of heat transfer parameters in a tricklebed. Hydrodynamics and flow regime transition study of trickle bed reactor at elevated temperature and pressure. Modification of ergun equation for application in trickle bed. Hydrogenation process of benzene is used as an example case. It is the simplest reactor for performing catalytic reactions. Numerical investigation of surface wettability on gas. Cfd modelling of tricklebed reactors for wastewater treatment. Reactor engineering and applications kindle edition by ranade, vivek v.
A trickle bed reactor is commonly known as a packed bed of stationary particle that are subjected to cocurrent gas and liquid flow at relatively low fluid superficial velocities. Twophase flow model for pressure drop and liquid holdup, formulation and experimental validation. Trickle bed reactors represent one of the most commonly used industrial reactors for performing chemical processes which involve solidcatalyzed reactions of gas and liquid phase reactants. Trickle bed reactors general information trickle bed reactors are solidliquidgas contacting devices wherein a liquid stream flows downward over a bed of catalyst with pressure difference serving as the driving force.
Trickle bed reactor an overview sciencedirect topics. Sastry computers and chemical engineering 23 1999 327. Hydrodynamics of trickle bed reactors at high pressure. The fluid flows over catalyst particles and forms fine films, rivulets or droplets. A flow map experiments for airwater and airacetone systems are performed in a pilot plant reactor of 0. In this study a cfd model has been developed for simulating two phase flow in the laboratory and commercial scales. The experimental setup mainly consists of a packedbed column of 50mm diameter, comprising of airliquid b. Influence of gas flow rate on liquid distribution in trickle. The word trickle clearly describes the flow pattern in a trickle bed reactor i.
Measurements and modeling by zeljko kuzeljevic a dissertation presented to the graduate school of arts and sciences of washington university in partial fulfillment of the requirements for the degree of doctor of philosophy august 2010 saint louis, missouri. Design and implementation of a simulator for the hydro. Hydrodynamics characteristics of hds trickle bed test reactor. A tricklebed reactor model for hydrogenation of 2,4. A trickle bed reactor tbr is a chemical reactor that uses the downward movement of a liquid and the downward cocurrent or upward countercurrent movement of gas over a packed bed of particles. Our offer for these cases is the biological trickle bed reactor. Cases have included an evaluation of trickle flow for systems with catalyst support particle size distributions, the study of prewetting effects on flow. Pdf analysis of the hydrodynamics of a periodically. Numerical investigation of multiphase flow hydrodynamics in trickle bed reactors conference paper pdf available august 2014 with 318 reads how we measure reads. Design of trickle bed reactors based on hydrodynamic parameters. Cfd modelling of trickle bed reactors for wastewater treatment 3 and maldistribution by using an axial dispersion model 2,3. Trickle bed reactor can be described as a fixed bed of catalyst particles. The performance of a tricklebed reactor is affected, not only by reaction kinetics, pressure, and temperature, but also by reactor hydrodynamics. Hydrogen sulfide is the product of hydrodesulfurization reaction and it is the inhibiter of the reaction.
Cfd prediction of hydrodynamics in highpressure trickle bed. The solid particles inside the reactor can be randomly packed or in definite patterns. The current investigation focuses on a number of aspects, both. Pdf computational fluid dynamics modeling of trickle bed. Hydrodynamics of trickle bed reactors tbrs packed with industrial catalyst.
Multiphase cfd modeling of tricklebed reactor hydrodynamics. As far as tbrs numerical modelling is concerned, many approaches have been considered hitherto to solve for the twophase flow in trickle bed reactors. Wallto bed or walltofluid heat transfer issues in trickle bed reactors tbr has an important impact on operation and efficiency in this category of reactors. Trickle bed reactor the material presented in this example is meant to serve as an introduction to trickle bed reactors. The hydrodynamics in a trickle bed reactor tbr in nonambient conditions are studied for airwater and airacetone pure organic liquid of low surface tension systems. The hydro cracking reactor of isomax unit of tehran refinery was considered as commercial scale reactor.
In this work, the hydrodynamics of trickle bed reactors were investigated with consideration of effects and conditions not typically reported in the literature. Pdf hydrodynamics and flow regime transition study of. Pdf trickle bed reactors are widely used in petroleum refining industry for various hydrotreating purposes to remove sulfur primarily from. The reactor model considers the main reactions present in the hydro desulfurization process. Analysis of the hydrodynamics of a periodically operated trickle bed reactor. Hydrodynamics and mass transfer in trickle bed reactors.
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