-
Improved Catalytic Activity of the High-Temperature Water Gas Shift Reaction on Metal-Exsolved La0.9Ni0.05Fe0.95O3 by Controlling Reduction Time -
Activated Carbons for Syngas Desulfurization: Evaluating Approaches for Enhancing Low-Temperature H2S Oxidation Rate -
Synthesis of Non-Cubic Nitride Phases of Va-Group Metals (V, Nb, and Ta) from Metal Powders in Stream of NH3 Gas under Concentrated Solar Radiation -
A Simple and Accurate Approach for Determining the VFA Concentration in Anaerobic Digestion Liquors, Relying on Two Titration Points and an External Inorganic Carbon Analysis -
Kinetic Studies of Cs+ and Sr2+ Ion Exchange Using Clinoptilolite in Static Columns and an Agitated Tubular Reactor (ATR)
Journal Description
ChemEngineering
ChemEngineering
is an international, peer-reviewed, open access journal on the science and technology of chemical engineering, published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science), Inspec, CAPlus / SciFinder, and many other databases.
- Journal Rank: CiteScore - Q2 (General Chemistry)
- Rapid Publication: First decisions in 15 days; acceptance to publication in 3 days (median values for MDPI journals in the second half of 2020).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Latest Articles
Performance Evaluation of the Electric Machine Cooling System Employing Nanofluid as an Advanced Coolant
ChemEngineering 2021, 5(3), 53; https://doi.org/10.3390/chemengineering5030053 (registering DOI) - 28 Aug 2021
Abstract
In this paper, the overall performance of an electric machine cooling system was examined in terms of heat transfer and fluid flow. The structure of the cooling system was based on the cooling jacket method. The cooling jacket contains spiral channels surrounding the
[...] Read more.
In this paper, the overall performance of an electric machine cooling system was examined in terms of heat transfer and fluid flow. The structure of the cooling system was based on the cooling jacket method. The cooling jacket contains spiral channels surrounding the stator and end-windings of the electric machine. Al2O3-water nanofluid is used inside the channels as the cooling fluid. The concentration of nanoparticles and the geometric structure of the cooling system have special effects on both aspects of heat transfer and fluid flow. Therefore, in this paper, the overall performance of the cooling system was evaluated by considering these effects. This study compared the importance of heat transfer and fluid flow performances on the overall performance of the cooling system. Numerical analyses were performed by 3D computational fluid dynamics and 3D fluid motion analysis. The analyses were carried out based on the 3D finite element method using the pressure-based solver of the Ansys Fluent software in steady mode.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
Open AccessArticle
Kinetic Study of the Ultrasound Effect on Acid Brown 83 Dye Degradation by Hydrogen Peroxide Oxidation Processes
ChemEngineering 2021, 5(3), 52; https://doi.org/10.3390/chemengineering5030052 (registering DOI) - 27 Aug 2021
Abstract
The effect of ultrasound on the degradation of the dye Acid Brown 83 by seven different degradation methods (blank test using only ultrasound, hydrogen peroxide in a neutral medium, hydrogen peroxide in a sulfuric acid medium and hydrogen peroxide in a sulfuric acid
[...] Read more.
The effect of ultrasound on the degradation of the dye Acid Brown 83 by seven different degradation methods (blank test using only ultrasound, hydrogen peroxide in a neutral medium, hydrogen peroxide in a sulfuric acid medium and hydrogen peroxide in a sulfuric acid medium in the presence of Fe(II), both without and with ultrasonic irradiation) is studied in this paper. The effectiveness of these methods is compared by analyzing the degradation percentages of the dye and its initial degradation rate. The application of ultrasound leads to a significant increase in the efficiency of any of the degradation method studied. Kinetic study of Acid Brown 83 degradation by the above-mentioned methods is carried out by using four kinetic models (first order, second order, Behnajady and pseudo-first order). The pseudo-first order model is the one that best fits the experimental data in all the used degradation methods. Although when the degradation is performed in the presence of Fe(II), the Behnajady model presents correlation coefficients slightly higher than those of the pseudo-first order, the maximum experimental conversions obtained fit much better in all cases to the pseudo first order model.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessArticle
Promising Isotope Effect in Pd77Ag23 for Hydrogen Separation
ChemEngineering 2021, 5(3), 51; https://doi.org/10.3390/chemengineering5030051 (registering DOI) - 27 Aug 2021
Abstract
Pd–Ag alloys are largely used as hydrogen separation membranes and, as a consequence, the Pd–Ag–H system has been intensively studied. On the contrary, fewer information is available for the Pd–Ag–D system; thus, the aim of this work is to improve the knowledge of
[...] Read more.
Pd–Ag alloys are largely used as hydrogen separation membranes and, as a consequence, the Pd–Ag–H system has been intensively studied. On the contrary, fewer information is available for the Pd–Ag–D system; thus, the aim of this work is to improve the knowledge of the isotope effect on the commercial Pd77Ag23 alloy, especially for temperature above 200 °C. In particular, deuterium absorption measurements are carried out in the Pd77Ag23 alloy in the temperature range between 79 and 400 °C and in the pressure range between 10−2 and 16 bar. In this exploited pressure (p) and composition (c) range, above 300 °C the pc isotherms display the typical shape of materials where only a solid solution of deuterium is present while at lower temperatures these curves seem to be better described by the coexistence of a solid solution and a deuteride in a large composition range. The obtained results are compared and discussed with the ones previously measured with the lightest hydrogen isotope. Such a comparison shows that the Pd77Ag23 alloy exhibits a clear inverse isotope effect, as the equilibrium pressure of the Pd–Ag–D system is higher than in Pd–Ag–H by a factor of ≈2 and the solubility of deuterium is about one half of that of hydrogen. In addition, the absorption measurements were used to assess the deuteration enthalpy that below 300 °C is ΔHdeut = 31.9 ± 0.3 kJ/mol, while for temperatures higher than 300 °C, ΔHdeut increases to 43 ± 1 kJ/mol. Additionally, in this case a comparison with the lighter isotope is given and both deuteration enthalpy values result lower than those reported for hydrogenation. The results described in this paper are of practical interest for applications operating above 200 °C, such as membranes or packing column, in which Pd77Ag23 has to interact with a gas stream containing both hydrogen isotopes.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessArticle
Optimizing the Control System of Clinker Cooling: Process Modeling and Controller Tuning
ChemEngineering 2021, 5(3), 50; https://doi.org/10.3390/chemengineering5030050 - 19 Aug 2021
Abstract
This paper aims to present efficient efforts to optimize the proportional-integral-differential (PID) controller of clinker cooling in grate coolers, which have a fixed grate and at least two moving ones. The process model contains three transfer functions between the speed of the moving
[...] Read more.
This paper aims to present efficient efforts to optimize the proportional-integral-differential (PID) controller of clinker cooling in grate coolers, which have a fixed grate and at least two moving ones. The process model contains three transfer functions between the speed of the moving grate and the pressures of the static and moving grates. The developed software achieves the identification of the model parameters using industrial data and by implementing non-linear regression methods. The design of the PID controller follows a loop-shaping technique, imposing as a constraint the maximum sensitivity, Ms, of the open-loop transfer function and providing a set of PIDs that satisfy a range of Ms. A simulator determines the optimal PID sets among those calculated at the design step using the integral of absolute error (IAE) as a performance criterion. The combination of a robustness constraint with a performance criterion, Ms and IAE respectively, leads to an area of controllers with Ms belonging to the range of 1.2 to 1.35. The IAE is between 4.2% and 4.8%, depending on the set-point value. PID sets located near the middle of this area can be chosen and implemented in the cooler’s routine operation.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessFeature PaperArticle
Microalgae Monitoring in Microscale Photobioreactors via Multivariate Image Analysis
ChemEngineering 2021, 5(3), 49; https://doi.org/10.3390/chemengineering5030049 - 11 Aug 2021
Abstract
Microscale photobioreactors for microalgae growth represent an interesting technology for fast data production and biomass characterization; however, the small scale poses severe monitoring challenges, as traditional methods cannot be used. Non-invasive techniques are therefore needed to quantify biomass concentration and other culture properties,
[...] Read more.
Microscale photobioreactors for microalgae growth represent an interesting technology for fast data production and biomass characterization; however, the small scale poses severe monitoring challenges, as traditional methods cannot be used. Non-invasive techniques are therefore needed to quantify biomass concentration and other culture properties, for example, pigment composition. To this purpose, a soft sensing approach based on multivariate image regression is proposed to exploit RGB images and/or PAM-imaging chlorophyll fluorescence. Different PLS (Partial Least Squares) regression models are used to estimate: (a) biomass concentration from the features extracted by RGB indices and/or PAM-imaging chlorophyll fluorescence measurements; and (b) Chlorophyll a content per cell from the features extracted by RGB indices and biomass concentration measurements. Every single model is aimed at characterizing the microalgae culture at different light intensities during batch growth. Results show that the proposed monitoring approach is as accurate as traditional measurement approaches and may represent a promising methodology for fast and inexpensive monitoring of microscale photobioreactors.
Full article
(This article belongs to the Special Issue Industrial Cultivation of Microalgae: Technologies, Applications and Challenges)
►▼
Show Figures

Figure 1
Open AccessArticle
In Silico Study of the Influence of Various Substrates on the Electronic Properties and Electrical Conductivity of Mono- and Bilayer Films of Armchair Single-Walled Carbon Nanotubes
ChemEngineering 2021, 5(3), 48; https://doi.org/10.3390/chemengineering5030048 - 09 Aug 2021
Abstract
We investigate electronic and electro-physical properties of mono- and bilayer armchair single-walled carbon nanotube (SWCNT) films located on substrates of different types, including substrates in the form of crystalline silicon dioxide (SiO2) films with P42/mnm and P3121
[...] Read more.
We investigate electronic and electro-physical properties of mono- and bilayer armchair single-walled carbon nanotube (SWCNT) films located on substrates of different types, including substrates in the form of crystalline silicon dioxide (SiO2) films with P42/mnm and P3121 space symmetry groups. The SWCNT films interact with substrate only by van der Waals forces. The densities of electronic states (DOS) and the electron transmission functions are calculated for SWCNT films with various substrates. The electrical conductivity of SWCNT films is calculated based on the electron transmission function. It is found that the substrate plays an important role in the formation of DOS of the SWCNT films, and the surface topology determines the degree and nature of the mutual influence of the nanotube and the substrate. It is shown that the substrate affects the electronic properties of monolayer films, changing the electrical resistance value from 2% to 17%. However, the substrate has practically no effect on the electrical conductivity and resistance of the bilayer film in both directions of current transfer. In this case, the values of the resistances of the bilayer film in both directions of current transfer approach the value of ~6.4 kΩ, which is the lowest for individual SWCNT.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Graphical abstract
Open AccessReview
Water Purification of Classical and Emerging Organic Pollutants: An Extensive Review
ChemEngineering 2021, 5(3), 47; https://doi.org/10.3390/chemengineering5030047 - 07 Aug 2021
Abstract
The main techniques used for organic pollutant removal from water are adsorption, reductive and oxidative processes, phytoremediation, bioremediation, separation by membranes and liquid–liquid extraction. In this review, strengths and weaknesses of the different purification techniques are discussed, with particular attention to the newest
[...] Read more.
The main techniques used for organic pollutant removal from water are adsorption, reductive and oxidative processes, phytoremediation, bioremediation, separation by membranes and liquid–liquid extraction. In this review, strengths and weaknesses of the different purification techniques are discussed, with particular attention to the newest results published in the scientific literature. This study highlighted that adsorption is the most frequently used method for water purification, since it can balance high organic pollutants removal efficiency, it has the possibility to treat a large quantity of water in semi-continuous way and has acceptable costs.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessFeature PaperArticle
Production of Sustainable Biochemicals by Means of Esterification Reaction and Heterogeneous Acid Catalysts
by
, , , , , , and
ChemEngineering 2021, 5(3), 46; https://doi.org/10.3390/chemengineering5030046 - 07 Aug 2021
Abstract
In recent years, the use of renewable raw materials for the production of chemicals has been the subject of different studies. In particular, the interest of the present study was the use of oleins, mixtures of free fatty acids (FFAs), and oleic acid
[...] Read more.
In recent years, the use of renewable raw materials for the production of chemicals has been the subject of different studies. In particular, the interest of the present study was the use of oleins, mixtures of free fatty acids (FFAs), and oleic acid to produce bio-based components for lubricants formulations and the investigation of the performance of a styrene-divinylbenzene acid resin (sPSB-SA) in the esterification reaction of fatty acids. This resin has shown good activity as a heterogeneous catalyst and high stability at elevated temperatures (180 °C). It was tested in the esterification reaction of oleic acid with 1,3-propanediol and of oleic acid with glycerol. In particular, the esterification reactions were performed in a steel stirred batch reactor and a PBR loop reactor. Tests were conducted varying the reaction conditions, such as alcohol type, temperature, reaction time, and catalysts, both homogeneous and heterogeneous ones. From the obtained results, acid resin (both in reticulated and not-reticulated form) showed high activity in esterification reaction of oleic acid with 1,3-propanediol and of oleic acid with glycerol and good resistance to the deactivation; thus, they can be considered promising candidates for future applications in continuous devices. Viscosity tests were performed, underlining the good properties of the obtained products as lubricant bases.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessArticle
Investigation and Computational Modelling of Variable TEG Leg Geometries
by
, , , , , and
ChemEngineering 2021, 5(3), 45; https://doi.org/10.3390/chemengineering5030045 - 04 Aug 2021
Abstract
In this work, computational modelling and performance assessment of several different types of variable thermoelectric legs have been performed under steady-state conditions and the results reviewed. The study conducted has covered geometries, not previously analysed in the literature, such as Cone-leg and Diamond-leg,
[...] Read more.
In this work, computational modelling and performance assessment of several different types of variable thermoelectric legs have been performed under steady-state conditions and the results reviewed. The study conducted has covered geometries, not previously analysed in the literature, such as Cone-leg and Diamond-leg, based on the corresponding thermoelectric generator leg shape structure. According to the findings, it has been demonstrated that the inclusion of a variable cross-section can have an impact on the efficiency of a thermoelectric generator. It has been concluded that the Diamond configuration generated a slightly larger voltage difference than the conventional Rectangular geometry. In addition, for two cases, Rectangular and Diamond configurations, the voltage generated by a TEG module consisting of 128 pairs of legs was analysed. As thermal stress analysis is an important factor in the selection of TEG leg geometries, it was observed based on simulations that the newly implemented Diamond-leg geometry encountered lower thermal stresses than the traditional Rectangular model, while the Cone-shape may fail structurally before the other TEG models. The proposed methodology, taking into account the results of the simulation carried out, provides guidance for the development of thermoelectric modules with different forms of variable leg geometry.
Full article
(This article belongs to the Special Issue Advanced Heat Exchangers for Waste Heat Recovery Applications)
►▼
Show Figures

Figure 1
Open AccessArticle
Characterization of Soluplus/ASC-DP Nanoparticles Encapsulated with Minoxidil for Skin Targeting
ChemEngineering 2021, 5(3), 44; https://doi.org/10.3390/chemengineering5030044 - 02 Aug 2021
Abstract
►▼
Show Figures
Soluplus (Sol) is an amphiphilic graft copolymer capable of forming self-assembled micelles and L-ascorbyl 2,6-dipalmitate (ASC-DP) aggregates spontaneously to form micelles. Micelles are used as drug carriers and can nanoparticulate drugs that are poorly soluble in water, such as minoxidil. The study aimed
[...] Read more.
Soluplus (Sol) is an amphiphilic graft copolymer capable of forming self-assembled micelles and L-ascorbyl 2,6-dipalmitate (ASC-DP) aggregates spontaneously to form micelles. Micelles are used as drug carriers and can nanoparticulate drugs that are poorly soluble in water, such as minoxidil. The study aimed to prepare minoxidil-encapsulated nanoparticles using Sol/ASC-DP and evaluate their potential for targeted skin application. Sol/ASC-DP nanoparticles or Sol/ASC-DP with minoxidil were prepared using the hydration method, and physical evaluations were carried out, including assessments of particle size and zeta potential. Particle structure was evaluated by transmission electron microscopy (TEM) and 1H-nuclear magnetic resonance spectra to assess particle stability and perform functional evaluations in skin penetration tests. TEM images showed spherical micelle-like particles of approximately 100 nm for Sol/ASC-DP at a 9:1 ratio and of approximately 80 nm for Sol/ASC-DP with incorporated minoxidil at a 9:1:0.5 ratio. Changes were also observed in the solid state, suggesting a hydrophobic interaction between Sol and ASC-DP. In addition, evaporated microparticles (Sol/ASC-DP/minoxidil = 9/1/0.5) improved the skin permeability of minoxidil. These results suggest that Sol/ASC-DP nanoparticles form a stable new nanoparticle due to hydrophobic interactions, which would improve the skin permeability of minoxidil.
Full article

Graphical abstract
Open AccessReview
A Review on Gas-Liquid Mass Transfer Coefficients in Packed-Bed Columns
ChemEngineering 2021, 5(3), 43; https://doi.org/10.3390/chemengineering5030043 - 02 Aug 2021
Abstract
This review provides a thorough analysis of the most famous mass transfer models for random and structured packed-bed columns used in absorption/stripping and distillation processes, providing a detailed description of the equations to calculate the mass transfer parameters, i.e., gas-side coefficient per unit
[...] Read more.
This review provides a thorough analysis of the most famous mass transfer models for random and structured packed-bed columns used in absorption/stripping and distillation processes, providing a detailed description of the equations to calculate the mass transfer parameters, i.e., gas-side coefficient per unit surface ky [kmol·m−2·s−1], liquid-side coefficient per unit surface kx [kmol·m−2·s−1], interfacial packing area ae [m2·m−3], which constitute the ingredients to assess the mass transfer rate of packed-bed columns. The models have been reported in the original form provided by the authors together with the geometric and model fitting parameters published in several papers to allow their adaptation to packings different from those covered in the original papers. Although the work is focused on a collection of carefully described and ready-to-use equations, we have tried to underline the criticalities behind these models, which mostly rely on the assessment of fluid-dynamics parameters such as liquid film thickness, liquid hold-up and interfacial area, or the real liquid paths or any mal-distributions flow. To this end, the paper reviewed novel experimental and simulation approaches aimed to better describe the gas-liquid multiphase flow dynamics in packed-bed column, e.g., by using optical technologies (tomography) or CFD simulations. While the results of these studies may not be easily extended to full-scale columns, the improved estimation of the main fluid-dynamic parameters will provide a more accurate modelling correlation of liquid-gas mass transfer phenomena in packed columns.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
Open AccessCommunication
2D Model of Transfer Processes for Water Boiling Flow in Microchannel
ChemEngineering 2021, 5(3), 42; https://doi.org/10.3390/chemengineering5030042 - 02 Aug 2021
Abstract
The modeling of transfer processes is a step in the generalization and interpretation of experimental data on heat transfer. The developed two-dimensional model is based on a homogeneous mixture model for boiling water flow in a microchannel with a new evaporation submodel. The
[...] Read more.
The modeling of transfer processes is a step in the generalization and interpretation of experimental data on heat transfer. The developed two-dimensional model is based on a homogeneous mixture model for boiling water flow in a microchannel with a new evaporation submodel. The outcome of the simulation is the distribution of velocity, void fraction and temperature profiles in the microchannel. The predicted temperature profile is consistent with the experimental literature data.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessArticle
MoS2-Cysteine Nanofiltration Membrane for Lead Removal
ChemEngineering 2021, 5(3), 41; https://doi.org/10.3390/chemengineering5030041 - 01 Aug 2021
Abstract
To overcome the limitations of polymers, such as the trade-off relationship between water permeance and solute rejection, as well as the difficulty of functionalization, research on nanomaterials is being actively conducted. One of the representative nanomaterials is graphene, which has a two-dimensional shape
[...] Read more.
To overcome the limitations of polymers, such as the trade-off relationship between water permeance and solute rejection, as well as the difficulty of functionalization, research on nanomaterials is being actively conducted. One of the representative nanomaterials is graphene, which has a two-dimensional shape and chemical tunability. Graphene is usually used in the form of graphene oxide in the water treatment field because it has advantages such as high water permeance and functionality on its surface. However, there is a problem in that it lacks physical stability under water-contacted conditions due to the high hydrophilicity. To overcome this problem, MoS2, which has a similar shape to graphene and hydrophobicity, can be a new option. In this study, bulk MoS2 was dispersed in a mixed solvent of acetone/isopropyl alcohol, and MoS2 nanosheet was obtained by applying sonic energy to exfoliate. In addition, Cysteine was functionalized in MoS2 with a mild reaction. When the nanofiltration (NF) performance of the membrane was compared under various conditions, the composite membrane incorporated by Cysteine 10 wt % (vs. MoS2) showed the best NF performances.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessFeature PaperArticle
Modelling Particle Agglomeration on through Elastic Valves under Flow
ChemEngineering 2021, 5(3), 40; https://doi.org/10.3390/chemengineering5030040 - 26 Jul 2021
Abstract
This work proposes a model of particle agglomeration in elastic valves replicating the geometry and the fluid dynamics of a venous valve. The fluid dynamics is simulated with Smooth Particle Hydrodynamics, the elastic leaflets of the valve with the Lattice Spring Model, while
[...] Read more.
This work proposes a model of particle agglomeration in elastic valves replicating the geometry and the fluid dynamics of a venous valve. The fluid dynamics is simulated with Smooth Particle Hydrodynamics, the elastic leaflets of the valve with the Lattice Spring Model, while agglomeration is modelled with a 4-2 Lennard-Jones potential. All the models are combined together within a single Discrete Multiphysics framework. The results show that particle agglomeration occurs near the leaflets, supporting the hypothesis, proposed in previous experimental work, that clot formation in deep venous thrombosis is driven by the fluid dynamics in the valve.
Full article
(This article belongs to the Special Issue Discrete Multiphysics: Modelling Complex Systems with Particle Methods)
►▼
Show Figures

Figure 1
Open AccessArticle
Optimization of Exopolysaccharide (EPS) Production by Rhodotorula mucilaginosa sp. GUMS16
ChemEngineering 2021, 5(3), 39; https://doi.org/10.3390/chemengineering5030039 - 21 Jul 2021
Abstract
Exopolysaccharides (EPSs) are important biopolymers with diverse applications such as gelling compounds in food and cosmetic industries and as bio-flocculants in pollution remediation and bioplastics production. This research focuses on enhancing crude EPS production from Rhodotorula mucilaginosa sp. GUMS16 using the central composite
[...] Read more.
Exopolysaccharides (EPSs) are important biopolymers with diverse applications such as gelling compounds in food and cosmetic industries and as bio-flocculants in pollution remediation and bioplastics production. This research focuses on enhancing crude EPS production from Rhodotorula mucilaginosa sp. GUMS16 using the central composite design method in which five levels of process variables of sucrose, pH, and ammonium sulfate were investigated with sucrose and ammonium sulfate serving as carbon and nitrogen sources during microbial incubation. The optimal crude EPS production of 13.48 g/100 mL was achieved at 1 g/100 mL of sucrose concentration, 14.73 g/100 mL of ammonium sulfate at pH 5. Variations in ammonium sulfate concentrations (1.27–14.73 g/100 mL) presented the most significant effects on the crude EPS yield, while changes in sucrose concentrations (1–5 g/100 mL) constituted the least important process variable influencing the EPS yield. The Rhodotorula mucilaginosa sp. GUMS16 may have the potential for large-scale production of EPS for food and biomedical applications.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Graphical abstract
Open AccessFeature PaperArticle
Intraparticle Model for Non-Uniform Active Phase Distribution Catalysts in a Batch Reactor
ChemEngineering 2021, 5(3), 38; https://doi.org/10.3390/chemengineering5030038 - 19 Jul 2021
Abstract
The study and the understanding of the importance of the morphological properties of heterogeneous catalysts can pave the way for important improvements in the performance of catalytic systems. Non-uniform active phase distribution catalysts are normally adopted for consecutive reactions to improve the selectivity
[...] Read more.
The study and the understanding of the importance of the morphological properties of heterogeneous catalysts can pave the way for important improvements in the performance of catalytic systems. Non-uniform active phase distribution catalysts are normally adopted for consecutive reactions to improve the selectivity to the desired intermediate product. Attributes on which minor attention is paid, such as the distribution and thickness of the active phase, can be decisive in the final rationale of the catalyst synthesis strategy. Starting from a previous work, where a single non-uniform active phase model for catalyst particles was developed, a key step to control the entire system is to include the bulk-phase equations and related transport phenomena. For this purpose, this work proposes a modeling approach of a biphasic reactive system in a batch reactor in the presence of three different kinds of catalytic particles (egg shell, egg white, and egg yolk) whose distinction lies in the localization of the active zone. The reactive network consists of a couple of reactions in series, which take place exclusively on the solid surface, and the intermediate component is the main product of interest. To reveal the influence related to the type of catalyst, an extensive parametric study was conducted, varying several structural coefficients to highlight the changes in the intraparticle and bulk concentration profiles of the different chemical species. The main results can be considered of wide interest for the chemical reaction engineering community, as it was demonstrated that mass and heat transfer limitations affect the catalyst performance. For the chosen system, the egg shell catalyst normally led to better catalytic performances.
Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
►▼
Show Figures

Figure 1
Open AccessArticle
Thermodynamic Design of Organic Rankine Cycle (ORC) Based on Petroleum Coke Combustion
by
ChemEngineering 2021, 5(3), 37; https://doi.org/10.3390/chemengineering5030037 - 16 Jul 2021
Abstract
Thermodynamic analysis of Organic Rankine Cycle (ORC) was performed in this work. The Petroleum Coke burner provided the required heat flux for the Butane Boiler. The simulation of pet-coke combustion was carried out by using Fire Dynamics Simulator software (FDS) version 5.0. Validation
[...] Read more.
Thermodynamic analysis of Organic Rankine Cycle (ORC) was performed in this work. The Petroleum Coke burner provided the required heat flux for the Butane Boiler. The simulation of pet-coke combustion was carried out by using Fire Dynamics Simulator software (FDS) version 5.0. Validation of the FDS calculation results was carried out by comparing the temperature of the gaseous mixture and CO2 mole fractions to the literature. It was discovered that they are similar to those reported in the literature. An Artificial Intelligence (AI) time forecasting analysis was performed on this work. The AI algorithm was applied to the temperature and soot sensor readings. Two Python libraries were applied in order to forecast the time behaviour of the thermocouple readings: Statistical model—ARIMA (Auto-Regressive Integrated Moving Average) and KERAS—deep learning library. ARIMA is a class of model that captures a suite of different standard temporal structures in time series data. Keras is a python library applied for deep learning and runs on top of Tensor-Flow. It has been developed in order to perform deep learning models as fast and easily as possible for research and development. The model accuracy and model loss plot shows comparable performance (train and test). Butane has been employed as a working fluid in the ORC. Butane is considered one of the best pure fluids in terms of exergy efficiency. It has low specific radiative forcing (RF) compared to Ethane and Propane. Moreover, it has zero ozone depletion potential and low Global Warming Potential. It is considered flammable, highly stable and non-corrosive. The thermodynamic properties of Butane needed to evaluate the heat rate and the power were calculated by applying the ASIMPTOTE online thermodynamic calculator. It was shown that the calculated net power of the ORC cycle is similar to the net power reported in the literature (relative error of 4.8%). The proposed ORC energetic system obeys the first and second laws of thermodynamics. The thermal efficiency of the cycle is 20.4%.
Full article
(This article belongs to the Special Issue Green Chemistry Technologies: Sustainable Approach to Chemical Engineering)
►▼
Show Figures

Graphical abstract
Open AccessFeature PaperReview
Development of Solid–Fluid Reaction Models—A Literature Review
ChemEngineering 2021, 5(3), 36; https://doi.org/10.3390/chemengineering5030036 - 15 Jul 2021
Abstract
►▼
Show Figures
A comprehensive review is carried out on the models and correlations for solid/fluid reactions that result from a complex multi-scale physicochemical process. A simulation of this process with CFD requires various complicated submodels and significant computational time, which often makes it undesirable and
[...] Read more.
A comprehensive review is carried out on the models and correlations for solid/fluid reactions that result from a complex multi-scale physicochemical process. A simulation of this process with CFD requires various complicated submodels and significant computational time, which often makes it undesirable and impractical in many industrial activities requiring a quick solution within a limited time frame, such as new product/process design, feasibility studies, and the evaluation or optimization of the existing processes, etc. In these circumstances, the existing models and correlations developed in the last few decades are of significant relevance and become a useful simulation tool. However, despite the increasing research interests in this area in the last thirty years, there is no comprehensive review available. This paper is thus motivated to review the models developed so far, as well as provide the selection guidance for model and correlations for the specific application to help engineers and researchers choose the most appropriate model for feasible solutions. Therefore, this review is also of practical relevance to professionals who need to perform engineering design or simulation work. The areas needing further development in solid–fluid reaction modelling are also identified and discussed.
Full article

Figure 1
Open AccessArticle
Coagulated Mineral Adsorbents for Dye Removal, and Their Process Intensification Using an Agitated Tubular Reactor (ATR)
by
, , , , and
ChemEngineering 2021, 5(3), 35; https://doi.org/10.3390/chemengineering5030035 - 06 Jul 2021
Abstract
The aim of this study was to understand the efficacy of widely available minerals as dual-function adsorbers and weighter materials, for the removal of toxic azo-type textile dyes when combined with coprecipitation processes. Specifically, the adsorption of an anionic direct dye was measured
[...] Read more.
The aim of this study was to understand the efficacy of widely available minerals as dual-function adsorbers and weighter materials, for the removal of toxic azo-type textile dyes when combined with coprecipitation processes. Specifically, the adsorption of an anionic direct dye was measured on various mineral types with and without the secondary coagulation of iron hydroxide (‘FeOOH’) in both a bench-scale stirred tank, as well as an innovative agitated tubular reactor (ATR). Talc, calcite and modified bentonite were all able to remove 90–95% of the dye at 100 and 200 ppm concentrations, where the kinetics were fitted to a pseudo second-order rate model and adsorption was rapid (<30 min). Physical characterisation of the composite mineral-FeOOH sludges was also completed through particle size and sedimentation measurements, as well as elemental scanning electron microscopy to determine the homogeneity of the minerals in the coagulated structure. Removal of >99% of the dye was achieved for all the coagulated systems, where additionally, they produced significantly enhanced settling rates and bed compression. The greatest settling rate (9 mm min−1) and solids content increase (450% w/w) were observed for the calcium carbonate system, which also displayed the most homogenous distribution. This system was selected for scale-up and benchmarking in the ATR. Dye removal and sediment dispersion in the ATR were enhanced with respect to the bench scale tests, although lower settling rates were observed due to the relatively high shear rate of the agitator. Overall, results highlight the applicability of these cost-effective minerals as both dye adsorbers and sludge separation modifiers to accelerate settling and compression in textile water treatment. Additionally, the work indicates the suitability of the ATR as a flexible, modular alternative to traditional stirred tank reactors.
Full article
(This article belongs to the Special Issue Role of Colloid and Surface Science in Decontaminating Ground and Groundwater Systems)
►▼
Show Figures

Figure 1
Open AccessReview
A Mini-Review of Enhancing Ultrafiltration Membranes (UF) for Wastewater Treatment: Performance and Stability
by
, , , , and
ChemEngineering 2021, 5(3), 34; https://doi.org/10.3390/chemengineering5030034 - 01 Jul 2021
Cited by 1
Abstract
The scarcity of freshwater resources in many regions of the world has contributed to the emergence of various technologies for treating and recovering wastewater for reuse in industry, agriculture, and households. Deep wastewater treatment from oils and petroleum products is one of the
[...] Read more.
The scarcity of freshwater resources in many regions of the world has contributed to the emergence of various technologies for treating and recovering wastewater for reuse in industry, agriculture, and households. Deep wastewater treatment from oils and petroleum products is one of the difficult tasks that must be solved. Among the known technologies, UF membranes have found wide industrial application with high efficiency in removing various pollutants from wastewater. It is shown that the search for and development of highly efficient, durable, and resistant to oil pollution UF membranes for the treatment of oily wastewater is an urgent research task. The key parameters to improve the performance of UF membranes are by enhancing wettability (hydrophilicity) and the antifouling behavior of membranes. In this review, we highlight the using of ultrafiltration (UF) membranes primarily to treat oily wastewater. Various methods of polymer alterations of the UF membrane were studied to improve hydrophilicity, the ability of antifouling the membrane, and oil rejection, including polymer blending, membrane surface modification, and the mixed membrane matrix. The influence of the type and composition of the hydrophilic additives of nanoparticles (e.g., Multiwall carbon nanotubes (MWCNT), graphene oxide (GO), zinc oxide (ZnO), and titanium dioxide (TiO2), etc.) was investigated. The review further provides an insight into the removal efficiency percent.
Full article
(This article belongs to the Special Issue Chemical Engineering and Multidisciplinary)
►▼
Show Figures

Figure 1
Highly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Applied Sciences, ChemEngineering, Membranes
Water Reclamation and Reuse
Editors-in-Chief: Jorge Rodríguez-Chueca, Marco S. LucasDeadline: 31 March 2022
Topic in
ChemEngineering, Clean Technol., IJERPH, Pollutants, Water
Emerging Solutions for Water, Sanitation and Hygiene
Editor-in-Chief: Panagiotis KaranisDeadline: 31 May 2022
Conferences
Special Issues
Special Issue in
ChemEngineering
Green Chemistry Technologies: Sustainable Approach to Chemical Engineering
Guest Editor: Maya TrofimovaDeadline: 30 August 2021
Special Issue in
ChemEngineering
Optimization of Operations and Processes in Chemical Engineering Involving Fluidization
Guest Editor: Cataldo De BlasioDeadline: 30 September 2021
Special Issue in
ChemEngineering
Role of Colloid and Surface Science in Decontaminating Ground and Groundwater Systems
Guest Editors: David Harbottle, Timothy HunterDeadline: 12 October 2021
Special Issue in
ChemEngineering
Design of Chemical and Light-Powered Micromotors
Guest Editor: Roberto María-HormigosDeadline: 29 October 2021


