The transport behavior of CO2 in the ionic liquids (ILs)‐electrode interface was revealed from the thermodynamic view via molecular dynamics simulations. The hopping and self‐diffusive mechanisms were identified in the interfacial and bulk region, and thereafter a hopping‐diffusion model was developed to evaluate the transport resistance of CO2 from bulk to the interface. Meanwhile, the vibrational

Considered one of the most versatile and widely used classical thermodynamic models to correlate phase equilibria behavior of nonideal systems, the nonrandom two‐liquid (NRTL) theory does not explicitly account for specific chemical associations such as hydrogen bonding. This deficiency has been recognized as the cause for unsatisfactory representation of association systems like methanol – alkanes

Multiple functional and hard‐to‐quantify sensorial product attributes that can be satisfied by a large number of cosmetic ingredients are required in the design of cosmetics. To overcome this problem, a new optimization‐based approach for expediting cosmetic formulation is presented. It exploits the use of a hierarchy of models in an iterative manner to refine the search for creating the highest‐quality

The direct experimental data for breakup parameters of drop breakup time, multiple breakage, and breakup rate are urgently required to understand drop breakup phenomena. In this regard, drop breakup experiments were carried out in a stirred tank using a high‐speed online camera. The influences of the rotating speed, interfacial tension, and drop viscosity on the above breakup parameters were then quantitatively

The bubble breakups in a jet bubbling reactor are captured using a high‐speed camera and the velocity field is measured by PIV. Two typical breakup patterns, jet breakup and jet‐vortex breakup are observed. The breakup time interval of the jet‐vortex breakup is two orders of magnitude higher than the jet breakup. The probability of the jet‐vortex breakup and the jet breakup accounting in the total

A transport model is proposed for wax deposition onto a cold finger from flowing wax‐containing oils. The model solves transient energy and mass balances simultaneously for a reversible first‐order kinetic rate for precipitation of pseudo‐single‐component wax, and the effects of yield stress using a critical solid wax concentration to withstand flow‐induced stress at the deposit‐fluid interface. The

The cell free system has been paid more attention due to its potential of facilitating efficient catalysis of multistep reactions. In this study, an efficient enzymatic cascade of glutathione (GSH) production was developed through the evolution of bifunctional glutathione synthetase (GshF), coupled with polyphosphate kinase (PPK). First, the stability and activity of GshF were enhanced by loop interchange

Research problems in the domains of physical, engineering, biological sciences often span multiple time and length scales, owing to the complexity of information transfer underlying mechanisms. Multiscale modeling (MSM) and high‐performance computing (HPC) have emerged as indispensable tools for tackling such complex problems. We review the foundations, historical developments, and current paradigms

Definitions for a local pressure in an inhomogeneous fluid are considered for both equilibrium and local equilibrium states. Thermodynamic and mechanical (hydrodynamic) contexts are reconciled. Remaining problems and uncertainties are discussed.

For chemical warfare agent removal, the humidity emerges as an unavoidable challenge that significantly affects the performance of metal–organic frameworks. In this work, via density functional theory calculations, ab initio molecular dynamics and classical molecular dynamics simulations, we investigate the structural and diffusion properties of water in the pristine defect‐free UiO‐66, one Zr‐based

Separation of higher hydrocarbons from methane is an important and energy‐intensive operation in natural gas processing. We present a detailed investigation of thin and oriented MFI zeolite membranes fabricated from 2D MFI nanosheets on inexpensive α‐alumina hollow fiber supports, particularly for separation of n‐butane, propane, and ethane (“natural gas liquids”) from methane. These membranes display

Combined cooling, heating, and power (CCHP) systems are promising solutions for conserving energy and reducing emissions. This article proposes a new mixed‐integer linear programming (MILP) model for simultaneous design and operation optimization of a renewable CCHP system, considering component nonlinear operating characteristics and performance degradation with time. A bi‐objective MILP problem is

In this presented work, a heavy petroleum fluid catalytic cracking (FCC) process model based on the use of a hybrid structural unit and bond‐electron matrix (SU‐BEM) framework on a molecular level has been developed. The SU‐BEM uses a simplified structural unit to represent the petroleum's molecular structure and chemical conversion, while retaining substantial details regarding atom‐connectivity.

Through particle‐resolved direct numerical simulations of flows past random arrays of oblate ellipsoids at low Reynolds numbers, this work demonstrates how the drag force on oblate ellipsoids depends on the Hermans orientation factor S, the mean crosswise sphericity φ⊥, the aspect ratio AR, and the solid volume fraction c. Wide ranges of S, AR, and c are considered and they are in the intervals (−0

Aspen Plus® simulations using the Peng‐Robinson (PR‐EOS) and the COSMO‐SAC models were performed to study absorption power cycles (APCs) using mixtures of R‐134a with two ionic liquids, [C2C1im][Tf2N] or [C6C1im][Tf2N], and compared against an R‐134a organic Rankine cycle (ORC) operating under similar conditions. The PR‐EOS results were in agreement with calculations from a PR model fitted to the R‐134a + IL

In the long‐wave approximation, a theoretical model is developed to describe waves in a rivulet flowing down the lower surface of an inclined cylinder. The model equations are derived by the weighted residual method by projecting the Navier–Stokes equations onto the constructed system of basic orthogonal polynomials. The simplest case of quasi‐two‐dimensional waves is studied in detail. The stability

C2H6/C2H4 separation is one of the most crucial processes in the chemical industry and currently practiced by energy‐intensive distillation technology. As an alternative, adsorption‐based separation is considered as technically feasible and economically viable, and there has been considerable interest to develop advanced adsorbents for C2H6/C2H4 separation. In this study, we computationally screen

This work demonstrates the optimization of the industrial scale chlorobenzene process, which continuously produces multiple products and includes a multiphase reaction with bubble column reactors (BCRs). The trust region filter (TRF) method is applied to carry out the demand‐based optimization of large chlorobenzene process with high‐fidelity BCR models. The TRF method uses surrogate models that substitute

A new method for the detailed design of shell and tube heat exchangers is presented through the formulation of coupled differential heat equations, along with algebraic equations for design variables. Heat exchanger design components (tube passes, baffles, and shells) are used to discretize the differential equations and are solved simultaneously with the algebraic design equations. The coupled differential

We propose a new strategy to synthesize heat exchanger networks with detailed designs of individual heat exchangers. The proposed strategy uses a multi‐step approach by first obtaining a heat exchanger network topology through solving a modified version of the mixed integer non‐linear programming (MINLP) stage‐wise superstructure (SWS) of Yee and Grossmann 1, which includes a smoothed LMTD approximation

Diverse engineering fields request flash calculations like isothermal flash, isenthalpic flash, and isentropic flash. They can be cast as minimization of a thermodynamic state function and solved by Michelsen's Q‐function approach. Flash calculationsforopensystems, i.e. systems where chemical potentials are specified instead of the mole numbers for some components, also belong to this scope. By analyzing

One of the major concerns in shale gas production is water management. Millions of gallons of water are injected to fracture each well and a significant amount returns to the surface as flowback. Operators are increasingly reusing flowback to reduce freshwater consumption and impaired water disposal. From that, networks of water pipelines in US shales are growing fast. This work is aimed at addressing

High fidelity three‐dimensional (3‐D) numerical simulations of commercial‐scale coal gasifiers are very time consuming and expensive. This article proposes a reduced‐order modeling approach that uses quasi one‐dimensional (1‐D) CFD–DEM simulation results to serve as an accurate initial condition for the 3‐D simulation, which significantly shortens the physical time from several hours to minutes to

Experimental results on pressure drop and flow patterns for gas–liquid flow through packed beds obtained in the International Space Station with two types of packing are presented and analyzed. It is found that the pressure drop depends on the packing wettability in the viscous–capillary (V–C) regime and this dependence is compared with previously published results developed using short duration low‐gravity

The knowledge of the local gas–liquid slip velocity distribution can offer a better understanding for the complex transport phenomena in bubble columns. In this work, CFD–PBM simulations are carried out to investigate the effect of superficial gas velocities, axial positions, and scale of bubble columns on the time‐averaged radial profiles of gas–liquid slip velocities. Furthermore, the relationship

In amine‐based CO2 capture processes, aqueous amine solvent is circulated between absorber (CO2 absorption) and stripping (solvent regeneration) columns. To reduce solvent regeneration energy demand, a selective membrane can dewater and enrich the CO2 concentration in solution prior to the stripper, lowering steam requirements for solution heating. In this work, a facile synthesis strategy was developed

In order to dynamically operate the gold cyanidation leaching process (GCLP) under uncertainty, a multi‐stage economic model predictive control (EMPC) is proposed for GCLP for the transient and steady‐state economic optimization. The proposed multi‐stage EMPC is composed of two steps. In the first step, the unmeasurable uncertain parameters are estimated by using Tikhonov regularization based method

Doped Ceria with abundant oxygen vacancies exhibits enhanced performance in heterogeneous oxidation. In principle, doping 50 mol% divalent cations (such as: Cu2+, Zn2+, and Mg2+) into CeO2 lattice would produce an exceptional catalyst with maximum active oxygen species. However, the huge size gap between Ce (IV) and divalent metal cations obstructs its synthesis. Here, we utilize the theory of increasing

Optimization‐constrained differential equations (OCDE) are a class of mathematical problems where differential equations are constrained by an embedded algebraic optimization problem. We analyze the well‐posedness of the local solutions of OCDE based on local optimality. By assuming linear independence constraint qualification and applying the Karush‐Kuhn‐Tucker optimality conditions, an OCDE is transformed

We propose an algorithm for scheduling subject to time‐variable electricity prices using nonlinear process models that enables long planning horizons with fine discretizations. The algorithm relies on a reduced‐space formulation and enhances our previous work (Schäfer et al., Comput Chem Eng, 2020;132:106598) by a sensitivity‐based refinement procedure. We therein expose the coefficients of the wavelet

Simultaneous evaluation of multiple time scale decisions has been regarded as a promising avenue to increase the process efficiency and profitability through leveraging their synergistic interactions. Feasibility of such an integral approach is essential to establish a guarantee for operability of the derived decisions. In this study, we present a modeling methodology to integrate process design, scheduling

Hybrid modeling has attracted increasing attention in order to take advantage of the additional data to improve process understanding. Current practice often adopts mechanistic models to predict process behaviors. These mechanistic models are based on physical understandings and experimental studies, but they sometimes lead to plant‐model mismatch (PMM) as they may be inaccurate to fully describe real

Support vector machines (SVMs) based optimization framework is presented for the data‐driven optimization of numerically infeasible differential algebraic equations (DAEs) without the full discretization of the underlying first‐principles model. By formulating the stability constraint of the numerical integration of a DAE system as a supervised classification problem, we are able to demonstrate that

In developing new adsorption separation processes, it is necessary to study both the equilibrium and dynamic adsorption properties of potential materials. Experimental determination of isotherms and dynamic breakthrough properties aid in the development of modeling new adsorption systems toward process development. Here, the equilibrium adsorption properties of a small‐pore zeolite, Na‐SSZ‐13, are

The physicochemical properties of protic ionic liquids (PILs) determine their industrial applications. In this study, six PILs based on 1‐vinylimidazole were synthesized, and their ionicities were determined by 1H NMR method. The thermodynamic properties, viscosities, densities, and conductivities of these PILs were correlated with the ionicities and the chain lengths of the anions. The ionicity was

Thermodynamic properties and fluid phase equilibria are crucial for the design and development of a chemical process. However, such data may not always be available, particularly for fine or specialty chemicals. In this work, we evaluate the reliability of using modern computational chemistry combined with recently developed predictive thermodynamic models to provide all the thermodynamic properties

A universal cohesive energy estimation equation for neutral molecules based on COSMO (COSMO‐UCE) was developed in this work; which comprises contributions from dispersive (nonpolar), polar (electrostatic) and hydrogen‐bonding interactions, and takes into account the influence of local segment surface charge density profile and entire molecule stereo charge distribution (dipole and quadrupole moment)

Confinement of molecules in nanoporous crystalline materials results in the unique and diverse characteristics of intracrystalline diffusion and adsorption, which can significantly affect the efficiency of gas separation and/or catalysis. However, understanding the interplay between confinement and intracrystalline diffusion and adsorption remains elusive at the quantitative level. In this work, it

Here we present a method for producing noncoalescing monodisperse microbubbles in an efficient, massive and controlled way. Since our prototype is easily scalable, it can be straightforwardly adapted to satisfy the specific gas injection demands required by the different applications where it can be used, like bioreactors or water treatment or purification plants. The main feature of the bubbling device

For “On Stability Analysis of Cascaded Linear Time Varying Systems in Dynamic Isotope Experiments” by Lin et al. ((https://doi.org/10.1002/aic.16911), published in the May 2020 AIChE Journal (Volume 66[5]), the authors request the following Erratum. In the Acknowledgment section, “National Key Research and Development Program (2017X7402003)” must be corrected to read “National Key Research and Development

This work proposes a framework for multistage adjustable robust optimization that unifies the treatment of three different types of endogenous uncertainty, where decisions, respectively,(i) alter the uncertainty set, (ii) affect the materialization of uncertain parameters, and (iii) determine the time when the true values of uncertain parameters are observed. We provide a systematic analysis of the

Algae‐to‐biodiesel processes are hindered by high costs and low energy return on investment.1,2. Herein, three foci in research improve algae‐to‐biodiesel processes by: (1) reducing high installation and energy costs in the CO2 sequestration, cultivation, and harvesting stages; (2) improving oil extraction and biodiesel generation; and (3) increasing utilization of the proteins in lipid‐extracted biomass

Modeling and analysis of the materials universeisan emerging area of research with many important applications in materials science. The main goal is to create a map of materials which allows not only to visualize and navigate the materials space, but also reveal complex relationships and “connections”among materials and potentially find clusters of materials with similar properties. In this paper

Vapor recompressed batch distillation (VRBD) is an energyintegrated configuration which works on the principle of a heat pump. Operation of such a column is challenging due to unsteady, nonlinear dynamics and strong interplay between separation and energy efficiency. In this paper, a two‐step approach is proposed for optimal operation and control of such a column. Initially, an openloop optimal operation

Optimization modeling tools are essential to determine optimal design specifications and operation conditions of polymerization processes, especially when quality indices based on molecular weight distributions (MWDs) must be enforced. This study proposes a generalized MWD‐based optimization strategy using orthogonal collocation in two dimensions, which can capture the dynamic features of MWDs accurately

Gas dispersion in non‐Newtonian fluids is a challenging task due to the formation of large cavities behind the impeller blades, which leads to the generation of very large bubbles. In this study, the effects of impeller speed, impeller type, pumping direction, and CMC concentration on the local and overall gas holdup inside a coaxial mixing tank comprised of two central impellers and an anchor were

Gibbs free energy minimization is employed to carry out thermodynamic equilibrium analysis studies of mixtures containing methane, carbon monoxide, carbon dioxide, water, and hydrogen ideal gases, and possibly solid carbon. The employed global minimization approach represents a general, unifying, conceptual framework that allows reaction and phase equilibrium analysis to be simultaneously carried out

This article addresses design modification to a flat‐blade static mixer to enhance mixing performance. The static mixer elements used in this work consist of four blades with curvature made to intensify turbulent‐like flow, while reducing the pressure drop. The blades were mounted on a cylindrical housing with 45° rotation relative to the axial direction. The mixer assembly was used in three different

This work explores the design of distributed model predictive control (DMPC) systems for nonlinear processes using machine learning models to predict nonlinear dynamic behavior. Specifically, sequential and iterative DMPC systems are designed and analyzed with respect to closed‐loop stability and performance properties. Extensive open‐loop data within a desired operating region are used to develop

Focal therapies such as hyperthermia have been successfully used to treat solid localized tumors; however, they are not easily applied to cancers that may present in a disseminated form such as ovarian cancer. To address this need, iron oxide (IO) particles were incorporated into microporous poly(caprolactone) scaffolds previously shown to recruit disseminating cancer cells. Under an alternating magnetic

Oscillating grids are frequently used with water and Newtonian fluids to generate controlled turbulence and mixing Yet, their use with shear thinning fluids still requires experimental characterization. Proper Orthogonal Decomposition (POD) is applied to PIV measurements of the flow generated by an oscillating grid in water and a shear thinning Dilute Polymer Solution (DPS) of Xanthan Gum. The aims

Alchemical perturbation density functional theory (APDFT) has promise for enabling computational screening of hypothetical catalyst sites. Here, we analyze errors in first order APDFT calculation schemes for binding energies of CHx, NHx, OHx, and OOH adsorbates over a range of different coverages on hypothetical alloys based on a Pt(111) reference system. We then train three different support vector

This work aims to characterize the mixing and suspension dynamics occurring within two commercially available DASGIP bioreactor configurations, equipped with a two‐blade paddle impeller with large impeller to tank diameter ratio, D/T = 0.97. Both continuous and intermittent agitation modes were employed to determine the impact that agitation strategy has upon mass transfer and microcarrier settling/suspension

Over the past few decades, several data‐driven methods have been developed for identifying a model that accurately describes the process dynamics. Lately, sparse identification of nonlinear dynamics (SINDy) has delivered promising results for various nonlinear processes. However, at any instance of plant‐model mismatch or process upset, retraining the model using SINDy is computationally expensive

The controlling filler aggregation and strengthening interfacial interaction are of great scientific significance for mixed matrix membranes (MMMs). In this study, the polymer‐embedded metal‐organic framework (pMOF) microspheres (MSs) are designed by one‐pot synthesis and employed as microfillers for improving separation performance of MMMs. Through adding polymer during solvothermal crystallization

Several commercially important chemical processes involve liquid–liquid phase separation. In the present work, we have developed a multi‐fluid Eulerian CFD model using OpenFOAM that incorporates binary and interfacial coalescence processes. We simulated separation of kerosene dispersed in water in a batch settler and validated the predictions using the measurements of time‐evolution of coalescing and

Experiments were performed at both normal and rather extreme Fischer–Tropsch Synthesis (FTS) operating conditions over a typical cobalt‐based catalyst, with the aim of exploring if aspects of the reaction mechanism could be elucidated. The results show that CO reacted when co‐feeding C2H4 with syngas, while CO did not react with H2 in absence of C2H4, under extremely low‐temperature conditions (140°C)

Bubble size distribution and bubble ellipticity were measured as a function of axial position in a vertically oriented semi‐batch gas–liquid Taylor vortex reactor with varying gas flow rate and inner cylinder rotation speed producing axial Reynolds numbers in the range 23.8–119 and azimuthal Reynolds numbers up to 4.2 × 104. The mean bubble size increases monotonically with axial distance from the