This paper addresses the problem of determining achievable set-points for artificial neural network (ANN)-based model predictive control (MPC) designs. In particular, this work considers a case where a first-principles model may not be readily available for a nonlinear process, while sufficient closed-loop data containing possibly correlated outputs is available, such that an ANN-based model that captures

Hydrophobic deep eutectic solvents (DESs) emerge as candidates to extract organic substrates from aqueous solutions. The DES-aqueous liquid–liquid interface plays a vital role in the extraction ability of DESs because the nonbulk structure of interfacial molecules could cause thermodynamic and kinetic barriers. One question is how the DES compositions affect the structural features of the interface

In shale gas field development, the major endogenous uncertainty comes from the production profile of candidate wells and its realization is dependent on the development decision. In this work, we apply multistage stochastic programming to address the shale gas field development planning problem under production profile uncertainty. Business realities such as budget limit and uncertainty resolution

To enhance hydrate formation kinetics, we presented a novel spiral-agitated reactor, where hydrates were synthetized in pure water systems, and fast hydrate kinetics was observed under extremely mild conditions. Hydrates can nucleate within 4 min under 3.5 MPa and 275.15 K at a rotating speed of 60 rpm, and large water-to-hydrate conversion (>85%) was obtained at a moderate condition of 4.85 MPa, 275

Polyelectrolytes may adopt rod- or coil-like conformations depending on the strength of intrachain repulsion and the effective charge density. The charge density of polyelectrolytes is influenced not only by the binding of small ions, but also by the binding with oppositely charged chains. We introduce a coupled variational approach that treats reversible ion binding, adaptive chain structure, and

Metaheuristic algorithms such as the Genetic Algorithm (GA) and Cuckoo Search (CS) algorithms have been widely used for phase equilibria computation. In the present work, correlation of the liquid-liquid splitting of 1,3-dioxolane + water and 1,4-dioxane + water mixtures using the buffers 3-n-morpholino-propanesulfonic acid (MOPS), 3-[4-(2-hydroxymethyl)-1-piperazinyl]-propanesulfonic acid (HEPPS)

The description of the mixing characteristics is of fundamental interest for modeling mass transport in fixed-bed reactors. A method based on Lagrangian parcel tracking is presented to determine the axial dispersion coefficient in the mechanical dispersion regime from particle-resolved computational fluid dynamics (CFD) results. The impact of fluid dynamic entry effects and the necessary averaging

Magnetic hyperthermia has been studied for the past two decades in cancer treatments as the local heat generated by magnetic nanoparticles under applied alternating magnetic fields is sufficient to kill cancer cells. More recently, it has been explored for controlling biological signaling through heat sensitive transmembrane channels. It is of great interest to produce magnetic nanoparticles with high

Modification of bifunctional Au-Ti catalysts for direct epoxidation of propylene with H2 and O2 is of burgeoning interest for potential commercialization requirements with desirable overall catalytic performance. Herein, we report a strategy by combining the addition of trace Pt into Au particles to enhance hydroperoxide species formation with the surface silylation to promote propylene oxide (PO)

Facilitated transport membrane containing a zero complex Ag4tz4 and 6FDA-TMPDA was fabricated via a solution-casting method and their separation performance toward C3H6/C3H8 was investigated. Ag4tz4 complexes were well dispersed in the polymeric matrix owing to the weak hydrogen bond between Ag4tz4 and 6FDA-TMPDA which can efficiently improve their interface compatibility. The reversible π complexation

First principles studies combined with the microkinetic analysis were performed to study the reliability and reaction mechanisms of single-atom-doped graphene materials in catalyzing NOx reduction with CO. By screening the 3d transition metals (Sc-Zn) and group IV elements (Si and Ge), it was found that the Ti- and Co-doped graphene sheets (TiGr and CoGr), respectively, exhibited excellent catalytic

In this work, a general model for artificial photosynthesis with capsule-immobilized enzyme was established based on ordinary differential equations, and a solution sequence was developed to get the analytical solution of the model equations. A coenzymes decomposition mechanism was incorporated into the model to improve the prediction ability for dynamic behavior of the reaction process. Then we showed

Herein, we report an asymmetric alicyclic polyamide nanofilm with an enhanced pore interconnectivity established by manipulating the molecular geometric structure, composed of a porous aromatic polyamide dendrimer layer and a dense alicyclic polyamide layer with hollow stripes. The experimental and simulated data demonstrate that the alicyclic polyamide nanofilm with an asymmetric structure exhibits

The mechanisms underlying homogeneous fluidization of Geldart A particles have long been debated. Recent experiments shed fresh insights that both a solid-like and a fluid-like state exist. Herein, 3D computational fluid dynamics-discrete element method simulations with the incorporation of interparticle van der Waals forces were performed for five typical Geldart A particles to investigate the bed

This study discusses the impact of the nonlinear relationship between nonlinear density-temperature and density-concentration on a nanofluid flow with Arrhenius activation energy and sinusoidal wall temperature variations. The highly nonlinear partial differential equations that model the nanofluid flow are solved using the bivariate spectral local linearization method. In literature, it is known that

Optimal tip sonication settings, namely tip position, input power, and pulse durations, are necessary for temperature sensitive procedures like preparation of viable cell extract. In this paper, the optimum tip immersion depth (20–30% height below the liquid surface) is estimated which ensures maximum mixing thereby enhancing thermal dissipation of local cavitation hotspots. A finite element (FE) heat

Cu+-containing materials have great potentials in various applications like adsorptive desulfurization. Nevertheless, their applications are severely obstructed by poor stability of Cu+ in air. Here, we first clarify the mechanism of Cu+ oxidation by first-principle calculations and demonstrate that moisture accelerates Cu+ oxidation dramatically. Then, the microenvironment of Cu2O-modified HKUST-1

Simulated moving bed (SMB) adsorption has potential for efficient separation of many valuable chemical mixtures, but considerably less attention has been devoted to multicomponent feeds relative to binary mixtures. We take a rigorous experimental and modeling approach to study multicomponent separation of aromatics and aliphatics with a mesoporous silica adsorbent, which is relevant in many petrochemical

Inorganic–organic hybrid films containing two-dimensional nanosheets have shown good gas barrier performance, but moderate tensile property, because of the rigid characteristics of covalent or ionic bonds between the assembly units. In this work, we used LDH nanosheets rich in hydroxyl groups as building units, followed by modification of tannic acid (TA), to assemble with polyethylene oxide (PEO)

This is a correction for “Yehuda Taitel, Dvora Barnea, A. E. Dukler. Modelling flow pattern transitions for steady upward gas–liquid flow in vertical tubes. AIChE Journal, 26 (3), 690260304. https://doi.org/10.1002/aic.690260304. A spelling error in the author name of Dvora Bornea has been corrected to Dvora Barnea which was done in the HTML and related PDF version of this article. We apologize for

Dufty, J., Wrighton, J., Luo, K., “Local pressure for inhomogeneous fluids” AIChE J. 2021; 67(3):e17037. The above article, published online on 30 August 2020 in Wiley Online Library (https://doi.org/10.1002/aic.17037), has been retracted by agreement between the authors, the journal Editor in Chief, Dr. Michael P. Harold, the American Institute of Chemical Engineers, and Wiley Periodicals LLC. The

The Capture and storage of toxic industrial chemicals such as H2S using porous polymer networks (PPNs) has shown promising application because of their high porosity, high surface area, high stability, low-cost and lightweight. In this work, 17,846 PPNs with the diamond-like topology were computationally screened to identify the optimal adsorbents for the removal of H2S and CO2 from humid natural gas

Artificial lift methods (ALMs) lift the accumulated fluids from horizontal shale-gas-producing wells and help sustain well performance. An artificial lift infrastructure plan includes the selection of ALMs and their operating schedule. This paper presents two discrete-time large-scale nonconvex mixed-integer nonlinear programming models to solve the artificial lift infrastructure planning problem.

The interaction of polypeptides and proteins with an inorganic surface is intrinsically dependent on the interfacial behavior of amino acids and sensitive to solution conditions such as pH, ion type, and salt concentration. A faithful description of amino-acid adsorption remains a theoretical challenge from a molecular perspective due to the strong coupling of local thermodynamic nonideality and inhomogeneous

Two-dimensional visualizations of point-source liquid spills in porous media were performed in a flat rectangular packed bed, emplaced on a robotized hexapod, to emulate roll/pitch marine oscillations. The extent to which the directional modulation of liquid gravity and the moving-bed inertial forces affect the liquid spills was the study's central aim. Spill morphology deviations were dictated by

Reactive transport softwares are today one of the cornerstones of environmental research. They contain multiphysics with very complex algorithms, including flow, transport, chemical, and sometimes heat transport, mechanical, and/or biological algorithms. Because of this complexity, some parts of these algorithms still have not been sufficiently studied. In this work, we focus on algorithms for activity

Establishment of a precise control model is conducive to efficient extraction of heteropolysaccharides (Hete) from lignocellulose biomass during alkali treatment process. Thus, this work focused on studying the dissolution behaviors of heteropolysaccharides from hemp stalk under different extraction conditions and developing a precise model to describe its solid–liquid mass transfer process. The results

Cyberattacks on process control systems (PCSs) may target communication links, compromising the data integrity. Cyberattack detection and mitigation are essential capabilities, since the consequences of a successful cyberattack on a PCS may be severe. While detectability may be viewed as a systems-theoretic property, cyberattack detectability in practice depends on the attack detection scheme used

Optimal power flow with close cooperation between the power grid and flexible electricity-intensive chemical processes can reduce costs for grid and electricity users. However, this would require sharing detailed chemical process models, which may reveal confidential information and potentially jeopardize competitive advantages for a chemical process. We propose an algorithm that enables economically

The oscillation-driven microbubble generation in a self-excited fluidic oscillator is explored in this work. By investigating the behaviors of bubbles, it is noted that for relatively low liquid flow rate, bubbles move upward directly and breakup does not occur inside the chamber region. Interestingly, the existence of bubbles could destroy the structure of flow field and even affect the oscillation

Although resonant motion of particles during mass flow discharge from silos has been extensively investigated by earlier researchers, the appearance of such phenomenon during funnel flow discharge has not been emphasized. In this work, the flow behavior of particles during funnel flow discharge from flat-bottomed silos has been investigated by conducting three-dimensional Discrete Element Method (DEM)

Drop sizes were investigated and measured in a Karr column. A stagewise population balance model was presented considering drop breakage and coalescence. The same breakage mechanisms observed in the single drop study were also found in column. The breakage probability model was selected by comparing the model from single drop study and the widely used models. Model parameters were calculated based

Adsorption of CO2 from post-combustion flue gas is one of the leading candidates for globally impactful carbon capture systems. This work focused on understanding the opportunities and limitations of sub-ambient CO2 capture processes utilizing a multistage separation process. A hybrid process design using a combination of pressure-driven separation of CO2 from flue gas (e.g., adsorption- or membrane-based

Deep eutectic solvents (DESs) are mixtures of two or more components that have lower melting temperatures compared to their constituting components. DESs possess many advantages, for example, low volatility, low flammability, and low toxicity, which make them promising alternatives to traditional organic solvents. The melting temperature, one of the important physical properties, is of essential importance

Realizing the stable high-flux flow of cohesive granular materials is a complicated subject. We experimentally studied the dynamic characteristics of cohesive granular materials discharged from hopper under modulated pulsed airflow. Results show that pulsed airflow with a smaller duty cycle can effectively trigger the stable flow of jammed cohesive granular materials. Furthermore, under proper working

Impellers in stirred vessels are often characterized by dimensionless numbers such as the power and flow numbers. These are often crucial in determining mixing performance. Previous studies for high-shear mixers have yielded correlations between the power, flow, and mixer geometries, since in these mixers the flow can be independently varied. For stirred vessels, dimensional analysis is typically used

This work presents an association-based activity coefficient model that explicitly considers the solution non-ideality due to associations among ions and solvent species. Built upon the electrolyte Nonrandom Two-liquid model (eNRTL), the model greatly improves the accuracy of eNRTL for strongly associating electrolyte solutions due to presence of ionic species with high surface charge density. The

The design of sensor networks for chemical plants is an important and complex task. In the context of data reconciliation, there are several desiderata for a sensor network, such as observability, redundancy (including hardware redundancy), and estimation precision, as well as good performance in the process optimization conducted after data reconciliation. While each of these aspects has been considered

Decomposition-based solution algorithms for optimization problems depend on the underlying latent block structure of the problem. Methods for detecting this structure are currently lacking. In this paper, we propose Stochastic Blockmodeling (SBM) as a systematic framework for learning the underlying block structure in generic optimization problems. SBM is a generative graph model in which nodes belong

In this work, the enumeration algorithms presented in Parts I and II for the globally optimal synthesis of minimal and non-minimal heat exchanger networks are extended to consider non-isothermal mixing. New mathematical models, including non-isothermal mixing constraints, are proposed to target the bounds of energy consumption and the binding exchanger minimum approximation temperature. These models

Deep neural networks (DNNs) based quantitative structure–property relationship (QSPR) studies are receiving increasing attention due to their excellent performances. A systematic methodology coupling multiple machine learning technologies is proposed to systematically solve vital problems including applicability domain and prediction uncertainty in DNN-based QSPR modeling. Key features are rapidly

CO2 hydrates are ice-like substances in which CO2 molecules are encapsulated in water and are known to reduce the rate at which CO2 dissolves in water. It is believed that the thickness of the hydrate film is dominant in the dissolution rate. In this study, we have developed a model that takes into account two factors: the permeation of H2O molecules and the change in film thickness. First, mass transfer

A bubble column was investigated as a method to achieve a desired and controllable rate of evaporation of a pharmaceutical solution. Applying a thermodynamic model to predict the rate of evaporation, all predicted values were observed to have accuracies within the bounds of instrumentation errors (<5% absolute). The developed model accounted for the measured effect of reduced vapor pressure, caused

This work aimed to intensify the mass transfer between fluidizing gas and Geldart-B nonmagnetizable particles by simultaneously introducing magnetizable particles and applying the magnetic field. The mere addition of magnetizable particles hardly affected the interphase mass transfer. Moreover, such mass transfer was not improved by the subsequent application of the magnetic field under the magnetization-LAST

Rheological modifiers are added to formulations to tune rheology, enable function and drive phase changes requiring an understanding of material structure and properties. We characterize two colloidal rod systems during phase transitions using multiple particle tracking microrheology, which measures the Brownian motion of probes embedded in a sample. These systems include a colloid (monodisperse polyamide

Understanding the thermal maturation mechanism of kerogen has both industrial and scientific significance. Here, kerogen extracted from Indian oil shale of Upper Assam basin is subjected to TG-FTIR analysis to study the thermal decomposition behavior of isolated kerogen and compared with oil shale sample. Kinetic study of kerogen was performed on thermogravimetric data using isoconversional methods

Electric field intensification has been demonstrated as an effective strategy for facilitating ion transfer and separation in polymer inclusion membrane (PIM) involved processes. However, it is still a challenge to develop compatible PIMs with high performance and to reveal the underlying mechanisms. Herein, crosslinked PIMs with different base polymers have been employed in PIM-electrodialysis processes

During the coating and drying of thin polymer-particle composites, the particle geometry has a big impact on the prediction of concentration profiles in the dry film. In this work, a plate-like geometry is used to evaluate the mass transport of the particles with the aspect ratio as a variable. The experimental determination of the viscosity and sedimentation rates allows to simulate concentration

Luminescent thermometry is a noninvasive method of temperature detection with high sensitivity and response speed. The present study demonstrated the process-intensified synthesis of ytterbium and erbium codoped calcium molybdate phosphors (CaMoO4:Yb3+/Er3+). The experiment involved the initial premixing of the precursors using a high-gravity rotating packed bed (RPB) reactor and subsequent calcination

There are some problems in gas–liquid stirred tank reactor (STR), such as low mass transfer efficiency, high exhaust gas oxygen concentration, and low product conversion rate, due to limitations of stirring speed and input power. This article summarizes the effect of adding circulating jet internals on bubble size distribution, overall gas holdup, gas–liquid volumetric mass transfer coefficient, and

We investigate the drying process of monodisperse colloidal film over a wide range of Péclet numbers (Pe) by using the Brownian dynamics simulation. We analyze the detailed process in three aspects; accumulation front, normal stress, and microstructure. The evolution of particle distribution is quantified by tracking the accumulation front. The accumulated particles contribute to the continuous increase

In this paper, the formation mechanism of droplets of shear-thinning non-Newtonian fluids in a step-emulsification microdevice is studied experimentally, by using aqueous solutions of sodium carboxymethyl cellulose (CMC) as the dispersed phase and cyclohexane as the continuous phase. According to the evolution of the front-end length of the dispersed thread over time, the droplet generation process

Sequential model-based design of experiments (MDBOE) accounts for information from previous experiments when selecting conditions for new experiments. In the current study, sequential MBDOE is used to select operating conditions for experiments in a batch-reactor that produces bio-based polytrimethylene ether glycol (PO3G). These Bayesian A-optimal experiments are designed to obtain improved estimates

Dual-reflux pressure swing adsorption (DR-PSA) is a state-of-art adsorption technology claiming to achieve both high product purity and recovery. However, its performance is inevitably limited by the gas mixing problem at the feed inlet position in adsorption columns, where a discontinuity in the columns' axial concentration profiles disturbs the separation. Here, we developed a dynamic-feed DR-PSA

Additive manufacturing is increasingly being used to develop innovative packings for absorption and desorption columns. Since distillation has not been in focus so far, this article aims to fill this gap. The objective is to obtain a miniaturized three dimensional (3D) printed packed column with optimized properties in terms of scalability and reproducibility, which increases process development efficiency

Bubbles rising through fluidized beds at velocities several times superficial velocities contribute to solids backmixing. In micro-fluidized beds, the walls constrain bubble sizes and velocities. To evaluate gas-phase hydrodynamics and identify diffusional contributions to longitudinal dispersion, we injected a mixture of H2, CH4, CO, and CO2 (syngas) as a bolus into a fluidized bed of porous fluid

SARS-CoV-2, a novel coronavirus spreading worldwide, was declared a pandemic by the World Health Organization 3 months after the outbreak. Termed as COVID-19, airborne or surface transmission occurs as droplets/aerosols and seems to be reduced by social distancing and wearing mask. Demographic and geo-temporal factors like population density, temperature, healthcare system efficiency index and lockdown

Liquid capillary-bridge formation between solid particles has a critical influence on the rheological properties of granular materials and, in particular, on the efficiency of fluidized bed reactors. The available analytical and semi-analytical methods have inherent limitations, and often do not cover important aspects, like the presence of non-axisymmetric bridges. Here, we conduct numerical simulations

Supply chain under demand uncertainty has been a challenging problem due to increased competition and market volatility in modern markets. Flexibility in planning decisions makes modular manufacturing a promising way to address this problem. In this work, the problem of multiperiod process and supply chain network design is considered under demand uncertainty. A mixed integer two-stage stochastic programming