Special Issue "Multiphase Reaction Engineering, Reactors and Processes "

A special issue of Processes (ISSN 2227-9717). This special issue belongs to the section "Chemical Processes and Systems".

Deadline for manuscript submissions: closed (31 March 2019).

Special Issue Editors

Dr. Muthanna H. Al-Dahhan
E-Mail Website
Guest Editor
Department of Chemical and Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA
Interests: multiphase reaction engineering; advanced measurement techniques; clean and alternative energy and environment
Dr. Tobias Bauer
E-Mail Website
Guest Editor
Department of Chemical Engineering, Technische Universität Dresden, 01062 Dresden, Germany
Interests: advanced processes; bio-economy and bio-refineries; new sensors; smart devices and advanced materials; energy conversion and storage

Special Issue Information

Dear Colleagues,

Multiphase reactors and processes play an indispensable role in process industries where their performance is one of the significant factor of the profitability of industry. Significant efforts and research have been devoted for understanding these reactors due to their complex interactions among the phases. However, with increasing cost, regulation requirements, competitiveness, new processes development and others, more efficient, intensified, reliable, controllable and predictable multiphase reactors are needed.  To achieve these goals, more studies are required to advance the fundamental understanding of the conventional and novel multiphase reactors, their scale-up approaches, intensification strategies, model development and validation, benchmarking data for CFD validation and many others.

This special issue on “Multiphase Reaction Engineering, Reactors and Processes” aims to address the recent developments and advancement in the multiphase reactors. Topics include, but are not limited to:

  • Fundamental understanding of the multiphase reactors
  • Novel multiphase reactors
  • Hydrodynamics
  • Scale – up methodologies and strategies
  • Reactor scale modeling
  • CFD modeling and simulation
  • Intensification of multiphase reactors

Prof. Dr. Muthanna H. Al-Dahhan
Dr. Tobias Bauer
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Processes is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1200 CHF (Swiss Francs). Please note that for papers submitted after 31 December 2019 an APC of 1400 CHF applies. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Multiphase
  • Modeling
  • Simulation
  • Intensification
  • Flow dynamics
  • Scale-up

Published Papers (9 papers)

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Research

Article
The Effect of Very Cohesive Ultra-Fine Particles in Mixtures on Compression, Consolidation, and Fluidization
Processes 2019, 7(7), 439; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7070439 - 10 Jul 2019
Cited by 2 | Viewed by 1387
Abstract
This paper focuses on the effect of ultra-fine ( d < 10 µm) powders in mixtures with fine ( d < 100 µm) bulk material on compression processes and also evaluates the re-fluidization behavior of the compressed bed (history effect). Achieving this goal, [...] Read more.
This paper focuses on the effect of ultra-fine ( d < 10 µm) powders in mixtures with fine ( d < 100 µm) bulk material on compression processes and also evaluates the re-fluidization behavior of the compressed bed (history effect). Achieving this goal, different mixtures of fine and ultra-fine Ground-Carbonate-Calcium were compressed at three pressure levels. The results show that by increasing the applied pressure, the compressibility decreases due to change in compaction regime. Subsequently, for the higher pressure, the slope of packing density versus applied stress curves is noticeably different. However, this slope does not depend on the size distribution of mixtures, but on the type of material. Comparing fluidization and re-fluidization curves (bed pressure drop vs. gas velocity) shows an increase in the maximum bed pressure drop ( Δ P p e a k ) for re-fluidization. By increasing the portion of ultra-fine particles in the binary mixture, Δ P p e a k increases in a non-linear manner. Furthermore, the incipient fluidization point moves to a higher gas velocity. After compression, the peak of the bed pressure drop in the re-fluidization test happens at a lower gas velocity than in the initial fluidization test. Thus, the slope of the loading curve is much larger for re-fluidization. The opposite is observed for the unloading curves. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
Comparison of Riser-Simplified, Riser-Only, and Full-Loop Simulations for a Circulating Fluidized Bed
Processes 2019, 7(5), 306; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7050306 - 22 May 2019
Cited by 3 | Viewed by 1261
Abstract
With the development of computing power, the simulation of circulating fluidized bed (CFB) has developed from riser-simplified simulation to riser-only simulation, then to full-loop simulation. This paper compared these three methods based on pilot-scale CFB experiment data to find the scope of application [...] Read more.
With the development of computing power, the simulation of circulating fluidized bed (CFB) has developed from riser-simplified simulation to riser-only simulation, then to full-loop simulation. This paper compared these three methods based on pilot-scale CFB experiment data to find the scope of application of each method. All these simulations, using the Eulerian–Eulerian two-fluid model with the kinetic theory of granular theory, were conducted to simulate a pilot-scale CFB. The hydrodynamics, such as pressure balance, solids holdup distribution, solids velocity distribution, and instantaneous mass flow rates in the riser or CFB system, were investigated in different simulations. By comparing the results from different methods, it was found that riser-simplified simulation is not sufficient to obtain accurate hydrodynamics, especially in higher solids circulating rates. The riser-only simulation is able to make a reasonable prediction of time-averaged behaviors of gas–solids in most parts of riser but the entrance region. Further, the full-loop simulation can not only predict precise results, but also obtain comprehensive details and instantaneous information in the CFB system. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
Study of Industrial Naphtha Catalytic Reforming Reactions via Modelling and Simulation
Processes 2019, 7(4), 192; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7040192 - 02 Apr 2019
Cited by 2 | Viewed by 2176
Abstract
Steady state and dynamic modelling and simulation of catalytic reforming unit of Kaduna Refining & Petrochemical Company, NNPC (Nigeria) was carried to find out the behaviour of the reactions under both steady and unsteady state conditions. The basic model together with kinetic and [...] Read more.
Steady state and dynamic modelling and simulation of catalytic reforming unit of Kaduna Refining & Petrochemical Company, NNPC (Nigeria) was carried to find out the behaviour of the reactions under both steady and unsteady state conditions. The basic model together with kinetic and thermodynamic parameters and properties were taken from the literature but is developed in gPROMs (an equation oriented modelling software) model building platform for the first time rather than in MATLAB or other modelling platform used by other researchers in the past. The simulation was performed using gPROMs and the predictions were validated against those available in the literature. The validated model was then used to monitor the behaviour of the temperature, concentrations of paraffins, naphthenes and aromatics with respect to both time and height of the reactor of the industrial refinery of Nigeria. Hydrogen yield, Research octane number (RON) and temperature profiles are also reported. The components behave similarly in terms of reactions in the reactors but the time to attain quasi-steady state is different. The results are in good agreement with the industrial plant data. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
A Novel Multiphase Methodology Simulating Three Phase Flows in a Steel Ladle
Processes 2019, 7(3), 175; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7030175 - 26 Mar 2019
Cited by 5 | Viewed by 1548
Abstract
Mixing phenomena in metallurgical steel ladles by bottom gas injection involves three phases namely, liquid molten steel, liquid slag and gaseous argon. In order to numerically solve this three-phase fluid flow system, a new approach is proposed which considers the physical nature of [...] Read more.
Mixing phenomena in metallurgical steel ladles by bottom gas injection involves three phases namely, liquid molten steel, liquid slag and gaseous argon. In order to numerically solve this three-phase fluid flow system, a new approach is proposed which considers the physical nature of the gas being a dispersed phase in the liquid, while the two liquids namely, molten steel and slag are continuous phases initially separated by a sharp interface. The model was developed with the combination of two algorithms namely, IPSA (inter phase slip algorithm) where the gas bubbles are given a Eulerian approach since are considered as an interpenetrating phase in the two liquids and VOF (volume of fluid) in which the liquid is divided into two separate liquids but depending on the physical properties of each liquid they are assigned a mass fraction of each liquid. This implies that both the liquid phases (steel and slag) and the gas phase (argon) were solved for the mass balance. The Navier–Stokes conservation equations and the gas-phase turbulence in the liquid phases were solved in combination with the standard k-ε turbulence model. The mathematical model was successfully validated against flow patterns obtained experimentally using particle image velocimetry (PIV) and by the calculation of the area of the slag eye formed in a 1/17th water–oil physical model. The model was applied to an industrial ladle to describe in detail the turbulent flow structure of the multiphase system. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
Multiphase Open Phase Processes Differential Equations
Processes 2019, 7(3), 148; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7030148 - 08 Mar 2019
Cited by 3 | Viewed by 1704
Abstract
The thermodynamic approach for the description of multiphase open phase processes is developed based on van der Waals equation in the metrics of Gibbs and incomplete Gibbs potentials. Examples of thermodynamic modeling of the multiphase and multicomponent A3B5 systems (In-Ga-As-Sb [...] Read more.
The thermodynamic approach for the description of multiphase open phase processes is developed based on van der Waals equation in the metrics of Gibbs and incomplete Gibbs potentials. Examples of thermodynamic modeling of the multiphase and multicomponent A3B5 systems (In-Ga-As-Sb and In-P-As-Sb) and Na+, K+, Mg2+, Ca2+//Cl, SO42−-H2O water–salt system are presented. Topological isomorphism of different type phase diagrams is demonstrated. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
Computational Fluid Dynamics (CFD) Simulations and Experimental Measurements in an Inductively-Coupled Plasma Generator Operating at Atmospheric Pressure: Performance Analysis and Parametric Study
Processes 2019, 7(3), 133; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7030133 - 04 Mar 2019
Cited by 2 | Viewed by 1405
Abstract
In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torch operating at 3 MHz are determined by direct measurement of radio-frequency (RF) current and voltage together with energy balance in the system. The variation of impedance with two parameters, namely the [...] Read more.
In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torch operating at 3 MHz are determined by direct measurement of radio-frequency (RF) current and voltage together with energy balance in the system. The variation of impedance with two parameters, namely the input power and the sheath gas flow rate for a 50 kW ICP is studied. The ICP torch system is operated at near atmospheric pressure with argon as plasma gas. It is observed that the plasma resistance increases with an increase in the RF-power. Further, the torch inductance decreases with an increase in the RF-power. In addition, plasma resistance and torch inductance decrease with an increase in the sheath gas flow rate. The oscillator efficiency of the ICP system ranges from 40% to 80% with the variation of the Direct current (DC) powers. ICP has also been numerically simulated using Computational Fluid Dynamics (CFD) to predict the impedance profile. A good agreement was found between the CFD predictions and the impedance experimental data published in the literature. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
The Effect of the Presence of Very Cohesive Geldart C Ultra-Fine Particles on the Fluidization of Geldart A Fine Particle Beds
Processes 2019, 7(1), 35; https://0-doi-org.brum.beds.ac.uk/10.3390/pr7010035 - 11 Jan 2019
Cited by 3 | Viewed by 2198
Abstract
The effect of the presence of ultra-fines (d < 10 μm) on the fluidization of a bed containing fine particles (d < 100 μm), is the subject of this paper. Practically, it can happen due to breakage or surface abrasion of [...] Read more.
The effect of the presence of ultra-fines (d < 10 μm) on the fluidization of a bed containing fine particles (d < 100 μm), is the subject of this paper. Practically, it can happen due to breakage or surface abrasion of the fine particles in some processes which totally changes the size distribution and also fluidization behaviour. The materials used in this study are both ground calcium carbonate (GCC); fine is CALCIT MVT 100 (Geldart’s group A) and ultra-fine is CALCIT MX 10 (group C). The experimental results for different binary mixtures of these materials (ultra-fines have 30%, 50%, or 68% of the total mixture weight) show that the physical properties of the mixtures are close to those of pure ultra-fine powders. Using mean values of the bed pressure drop calculated from several independent repetitions, the fluidization behaviour of different mixtures are compared and discussed. The fluidization behaviour of the mixtures is non-reproducible and includes cracking, channelling and agglomeration (like for pure ultra-fine powders). Increasing the portion of ultra-fine materials in the mixture causes a delay in starting partial fluidization, an increase in the bed pressure drop as well as a delay in reaching the peak point. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Article
Effect of Particle Size on Carbon Nanotube Aggregates Behavior in Dilute Phase of a Fluidized Bed
Processes 2018, 6(8), 121; https://0-doi-org.brum.beds.ac.uk/10.3390/pr6080121 - 08 Aug 2018
Cited by 6 | Viewed by 1639
Abstract
Fluidized bed reactors have been increasingly applied for mass production of Carbon Nanotube (CNT) using catalytic chemical vapor deposition technology. Effect of particle size (dp = 131 μm and 220 μm) on fluidization characteristics and aggregation behavior of the CNT particles [...] Read more.
Fluidized bed reactors have been increasingly applied for mass production of Carbon Nanotube (CNT) using catalytic chemical vapor deposition technology. Effect of particle size (dp = 131 μm and 220 μm) on fluidization characteristics and aggregation behavior of the CNT particles have been determined in a fluidized bed for its design and scale-up. The CNT aggregation properties such as size and shape were measured in the dilute phase of a fluidized bed (0.15 m-ID × 2.6 m high) by the laser sheet technique for the visualization. Two CNT particle beds showed different tendency in variations of the aggregates factors with gas velocity due to differences in factors contributing to the aggregate formation. The CNT particles with a larger mean size presented as relatively larger in the aggregate size than the smaller CNT particles at given gas velocities. The aggregates from the large CNT particles showed a sharp increase in the aspect ratio and rapid decrease in the roundness and the solidity with gas velocity. A possible mechanism of aggregates formation was proposed based on the variations of aggregates properties with gas velocity. The obtained Heywood diameters of aggregates have been firstly correlated with the experimental parameter. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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Communication
A New Concept of Stirred Multiphase Reactor Using a Stationary Catalytic Foam
Processes 2018, 6(8), 117; https://0-doi-org.brum.beds.ac.uk/10.3390/pr6080117 - 07 Aug 2018
Cited by 3 | Viewed by 1727
Abstract
Developing new stirred gas–liquid–solid reactors with high mass transfer capabilities is still a challenge. In this publication, we present a new concept of multiphase reactor using a stationary catalytic foam and a gas-inducing impeller. The gas–liquid (GL) and liquid–solid (LS) mass transfer rates [...] Read more.
Developing new stirred gas–liquid–solid reactors with high mass transfer capabilities is still a challenge. In this publication, we present a new concept of multiphase reactor using a stationary catalytic foam and a gas-inducing impeller. The gas–liquid (GL) and liquid–solid (LS) mass transfer rates in this reactor were compared to a stirred reactor with basket filled with beads. Batch absorption of hydrogen and measurement of α-methylstyrene hydrogenation rate on Pd/Al2O3 catalyst were used to evaluate kGLaGL coefficients and kLS coefficients, respectively. With similar LS transfer rates to the basket-reactor and much higher GL transfer rates, the new reactor reveals a very promising tool for intrinsic kinetics investigations. Full article
(This article belongs to the Special Issue Multiphase Reaction Engineering, Reactors and Processes )
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