A predictive model based on Fick's second law for radial diffusion is proposed and validated for modeling the diffusion of fragrance materials. A pure component, two binary systems, and a ternary system were used for validation. The model combines the prediction model to represent the liquid phase nonidealities, using the UNIFAC group contribution method, with the Fickian radial diffusion approach

As a novel green chemical building block, it is of significance to increase the productivity of 5-hydroxymethylfurfural (HMF) derived from hexoses. In our work, a catalytic system efficiently converting glucose to HMF was designed, which is guided by catalytic coupling at multiple length scales. A catalyst from the sulfonated and carbonized glucose with aluminum loading containing Lewis and Brønsted

The roles of interaction between two catalyst components in CuO-ZnO-ZrO2-Al2O3 (CZZA)/HZSM-5 bifunctional catalyst for dimethyl ether (DME) synthesis via carbon dioxide hydrogenation were investigated. It was found that CZZA catalyst showed excellent stability during methanol (MeOH) synthesis for 100 hrs, while there was a severe loss of catalytic activity in the bifunctional catalyst for DME synthesis

Although great progress has been made in the synthesis of hierarchically structured zeolites (HSZs), the optimal design of HSZs is still very challenging due to the lack of mathematical models. This work proposes a multiscale model that is able to describe mass transfer and reaction at crystal, pellet, and reactor levels, by directly coupling model equations at two neighboring levels. Two types of

Air pollution has posed health and environmental threats since the Industrial Revolution. Technological solutions present major expenses for industry, yet nature's ecosystems also provide pollution uptake. In the pursuit of techno-ecological sustainable design, this work presents a framework for spatially-explicit industrial site design that determines where and when ecological restoration should be

Computational screening was employed to calculate the enantioseparation capabilities of 45 functionalized homochiral metal-organic frameworks (FHMOFs), and machine learning (ML) and molecular fingerprint (MF) techniques were used to find new FHMOFs with high performance. With increasing temperature, the enantioselectivities for (R,S)-1,3-dimethyl-1,2-propadiene are improved. The “glove effect” in the

Njs, the minimum agitation speed to just-suspend dispersed solids in liquids in stirred tanks, is a critical parameter to operate industrial processes. The focus of this work was to develop a novel observer-independent method to experimentally obtain Njs in tanks that cannot be visually inspected internally using Electrical Resistance Tomography (ERT). The mean bulk resistivity was measured across

The dynamic adsorption isotherms of CO2-EGR were measured by using an Intelligent Gravimetric Analysis system. In the initial CO2 injecting stage, all the injected CO2 enters into the adsorbent and the mole fraction of CH4 in the gas phase () is maintained at 1.0. The CH4 recovery factor () increases. The duration of this stage (tCD) depends on the selectivity of CO2 over CH4 (). An adsorbent with

To deeply understand the role of surfactants on the acid/C4 hydrocarbon miscibility, the catalytic activity and molecular-level interfacial properties of long-alkyl-chain cationic surfactants (hexadecyltrimethylammonium bromide, CATB and dihexadecyldimethylammoniumchloride, DDAB) and anionic one (sodium dodecyl benzene sulfonate, SDBS) were studied as additives for H2SO4 alkylation using experiments

Herein, we demonstrate a kinetics and a mechanistic strategy to disentangle the origins of the significantly improved activity and selectivity of Pt-catalyzed glycerol oxidation. The unchanged reactant reaction orders and activation energies suggest the same kinetics despite variable Pt particle sizes, based on which a Michaelis–Menten kinetics treatment is conducted to individually quantify the number

A new method for integrated ionic liquid (IL) and absorption process design is proposed where a rigorous rate-based process model is used to incorporate absorption thermodynamics and kinetics. Different types of models including group contribution models and thermodynamic models are employed to predict the process-relevant physical, kinetic, and thermodynamic (gas solubility) properties of ILs. Combining

Dynamic real-time optimization (DRTO) is a supervisory strategy at the upper level of the industrial process automation architecture that computes economically optimal set-point trajectories that are in turn passed on to the lower-level model predictive control (MPC) for tracking. The economically optimal solution, in several process industries, could lead to operating the plant at or around an unstable

This study performs data-driven modeling of mesoscale solids stress closures for filtered two-fluid model (fTFM) in gas–particle flows via an artificial neural network (ANN) based machine learning method. The data used for developing the ANN-based predictive data-driven modeling framework is systematically filtered from fine-grid simulations. The loss function optimization result reveals that coupling

We numerically investigate the effect of liquid cohesion on the clogging of microchannels induced by small wet particles. The computer simulation is performed by the discrete element method (DEM) with cohesive contact models in presence of pendular liquid bridges, which is embedded into the computational fluid dynamics (CFD). We find that liquid cohesion significantly promotes particle deposition and

Particle crushing is commonly encountered during the storage, transportation, and handling of granular assemblies. This work is aimed at ascertaining the applicability of four particle breakage criteria frequently mentioned in literature. Discrete element method (DEM) simulations were conducted to investigate the crushing of spherical aggregates under multicontact loadings. Mean and major principal

Holistic catalytic reactors with fractal structures have attracted growing attention in heterogeneous reactions because of their advantages of improved mass transfer and easy separation. Herein, a cost-efficient and straightforward design strategy that combined three-dimensional printing and electroless deposition was presented to construct dynamic, holistic stirred reactors with the fractal structure

Propane dehydrogenation (PDH) is one of the most effective methods to produce propylene. But the industrial Pt-based catalysts often suffer from short-term stability under the high temperature reaction environment (500–700°C) via sintering and coke deposition. Herein, stable PDH reaction in high propylene yield has been achieved by the confinement of Pt–Zn intermetallic alloys (IMAs) in the channels

In this study, traditional Monte Carlo simulation and density functional theory-based structural optimization methods were combined to screen computation-ready experimental metal-organic framework (MOF) database for the application of natural gas purification. Our results show that about half of the good performing computation-ready experimental MOF structures displayed various degrees of deformation

The calculation of volume roots from cubic equation of state, for given temperature and pressure, is still an important operation both in industry and academic field. It is proposed the use of Ferrari's formula to calculate the pressure range containing three real positive roots (for pressure and temperature below the critical). In addition, a modification in the Cardano-Tartáglia's formula is proposed

In Parts I, II, and III, the Hu-Lee-Sum (HLS) correlation was demonstrated to be a robust method for determining the hydrate suppression temperatures for structure I and II hydrates containing inorganic salts and organic inhibitors. Here, Part IV introduces two different approaches to estimate the water activity for systems containing inhibitors: ice melting point and activity coefficient models. The

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

When a fault occurs in a process, it slowly propagates within the system and affects the measurements triggering a sequence of alarms in the control room. The operators are required to diagnose the cause of alarms and take necessary corrective measures. The idea of representing the alarm sequence as the fault propagation path and using the propagation path to diagnose the fault is explored. A diagnoser

A large set of industrial wicks made from sintered polymer beads and fibrous materials were studied. Three types of liquid fronts were observed: sharp, semi-sharp, and diffuse. The bead-like microstructure with lower porosity is found to support sharp fronts, while the aligned-fiber microstructure with higher porosities leads to a smudging/diffusing of the fronts. The previously developed sharp-front

We combine reduced order modelling and system identification to reconstruct the temporal evolution of large scale vortical structures behind the blades of a Rushton impeller. We performed Direct Numerical Simulations at Reynolds number 600 and employed proper orthogonal decomposition (POD) to extract the dominant modes and their temporal coefficients. We then applied the identification algorithm, N4SID

The detailed experimental investigation of an oscillating bubble plume created in a quasi-two-dimensional bubble column is reported for low void fraction and millimeter bubbles. The plume exhibits periodic oscillations and generates large-scale coherent structures in the liquid. The local and transient hydrodynamics of this bubbly flow was investigated with particle-image velocimetry (PIV) in the liquid

The kinetics experiments of fast reaction process of propylene chlorination at low temperature (30–90°C) and high temperature (420–480°C) are respectively conducted, and the corresponding reaction mechanisms and kinetics models are proposed. The radical mechanism at high temperature and the molecular mechanism at low temperature are found to be most likely with the experimental results. Specifically

A spatially resolved one dimensional pressure filtration model was developed for a slurry of edible fat crystals. The model focuses on the expression step in which a cake is compressed to force the liquid through a filter cloth. The model describes the local oil flow in the shrinking cake modeled as a porous nonlinear elastic medium existing of two phases, viz. porous aggregates and interaggregate

Hydrothermal liquefaction (HTL), a thermo-chemical conversion process, uses water as a reaction medium at elevated pressure and temperature, to convert biomass to renewable liquid fuel and recovers fertilizer-rich water. To assess the techno-economic screening of HTL oils from various feedstock, it is crucial to have information on molecular composition of the feed and products. There are limitations

The Sabatier process is promising for carbon dioxide utilization and energy storage. However, the serious problem that limits more comprehensive industrial applications is catalyst deactivation due to the temperature runaway phenomenon. The inert particle dilution approach, including the mixing dilution method and layered dilution method is applied to solve this problem. Based on the lattice kinetic

Much confusion exists on whether force- or energy-based descriptions of cohesive-particle interactions are more appropriate. We hypothesize a force-based description is appropriate when enduring-contacts dominate and an energy-based description when contacts are brief in nature. Specifically, momentum is transferred through force-chains when enduring-contacts dominate and particles need to overcome

The concept of an association dependent hard sphere diameter is introduced as a means to obtain an accurate PC-SAFT equation of state model for water. The new approach is demonstrated to be a step change in accuracy for the representation of pure water properties as compared to standard PC-SAFT applications. Extension of the approach to mixtures is discussed.

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We present a framework for the formulation and solution of continuous process scheduling problems. We focus on modeling transient operations such as startups, shutdowns, and transitions between steady states. First, we show how the concept of processing tasks can be generalized to represent continuous processes, including their transient operations. Second, we discuss how to systematically calculate

To solve multistage adaptive stochastic optimization problems under both endogenous and exogenous uncertainty, a novel solution framework based on robust optimization technique is proposed. The endogenous uncertainty is modeled as scenarios based on an uncertainty set partitioning method. For each scenario, the adaptive binary decision is assumed constant and the continuous variable is approximated

Considering capillary force, viscous force, and gravity and buoyancy effects due to the oil–water density difference during the imbibition process, a new mathematical model for core-scale spontaneous imbibition considering gravity and buoyancy is established. The imbibition rates with and without gravity and buoyancy in high-, low-, and ultralow-interfacial tension (IFT) solutions are compared. The

Membrane fouling continues to hamper the performance of membrane-filtration processes. A challenge with macromolecular foulants like proteins is that macroscopic characterizations, like net electrical charge, may be poorly correlated with membrane fouling. This necessitates a molecular-scale analysis of the local interactions. In this study, molecular dynamics simulations have been performed to understand

We present an approach for parameter estimation with multirate measurements, with the slow measurements having variable time delays due to laboratory analysis, and also being functions of all the states during the sample collection. We formulate a particle filter-based approach under the framework of the expectation maximization algorithm to develop the estimates. The effectiveness and applicability

A generic model for the prediction of critical gas velocity and pressure gradient in slightly inclined pipes (β ≤ 6°) is presented in this article. The gas–liquid configuration was determined based on the minimum energy principle and consideration of wettability and surface tension. A visualization experiment was conducted to obtain the critical gas velocity and the critical pressure gradient of a

In chemical manufacturing processes, equipment degradation can have a significant impact on process performance or cause unit failures that result in considerable downtime. Hence, maintenance planning is an important consideration, and there have been increased efforts in scheduling production and maintenance operations jointly. In this context, one major challenge is the inherent uncertainty in predictive

Low organic carbon-to-nitrogen ratio and existing sulfate (SO42−) in industrial wastewater limited nitrogen removal. Coupling SO42- reduction with sulfide autotrophic denitrification provides a novel strategy. Herein, bioelectrochemical sulfate reduction was coupled with heterotrophic sulfate reduction to drive sulfide autotrophic denitrification. In this coupled system, total nitrogen (TN) removal

A series of Pt/HPMo/SBA-15 catalysts with the pore size as a single variable were prepared to elucidate the internal diffusion effect on the hydrotreatment of n-C16. A novel model was developed to calculate the Weisz-Prater number (NW-P) because the traditional model relies on excessive empirical reference values and affects the accuracy remarkably. The utilization of the internal effectiveness factor

Cylindrical lamps are usually equipped in the tubular UV reactor to offer UV radiation. This paper describes the axisymmetric characteristics of UV radiation from the cylindrical UV lamp. Axisymmetric lamp emission models are developed in a two-dimensional axisymmetric space for the line source, the superficial source and the volumetric source. The present axisymmetric lamp emission models are easy

This study proposed an isotope-tagging method to investigate reactions under the atmosphere of product gas. To illustrate this method, the calcination kinetics of calcium carbonate Ca13CO3 in CO2 atmospheres were investigated by monitoring 13CO2 produced using a micro fluidized bed reaction analyzer (MFBRA). The results demonstrated that the presence of CO2 in reaction atmosphere increases the apparent

This study presents a novel stochastic optimization method for the efficient synthesis of large-scale nonsharp distillation systems, where heat integration and thermal coupling can be involved simultaneously. A new binary tree encoding method was developed to represent distillation sequences with no limits on the number of middle components in nonsharp splits to ensure a complete solution space. Thermally

This paper presents results of measurements performed in uncovered baffled and unbaffled stirred tanks. The Laser Doppler Anemometry (LDA) set consists of a 300 mW argon-ion laser generating two pairs of blue and green beams. Additionally, three turbulence models are verified to simulate mixing dynamics in uncovered baffled and unbaffled stirred tanks. Simulations are performed using both the steady-

This article investigates the effect of inlet shape, entrance length, and turbulence promoters on mass transfer by using 3D-printed electrolyzers. Our results show that the inlet design can promote turbulence and lead to an earlier transition to turbulent flow. The Reynolds number at which the transition occurs can be predicted by the ratio of the cross-sectional area of the inlet to the cross-sectional

Correction to: Keeping chemical engineering education relevant. FIGURE 4 Open in figure viewerPowerPoint Smoke accumulation A decision was made to show a man smoking a cigarette in a small room. Article has been corrected online at https://aiche.onlinelibrary.wiley.com/doi/10.1002/aic.17203 Source: Jan Koutek, @koutek_photo, Unsplash, https://unsplash.com/photos/xf585wov7TU

This work presents the application of a Koopman operator approach to a batch pulp digester. To manufacture paper products with desired properties, it is essential to consider both macroscopic and microscopic attributes of pulp. However, the complexity of multiscale dynamics of pulping processes hinders proper control system design. Therefore, we utilize extended dynamic mode decomposition (EDMD), which

The mechanisms involved in premixed magnesium and hydrogen hybrid and synthetic MgH2 dust cloud explosions were investigated. The results revealed that trace amounts of H2 in Mg explosions can markedly increase explosion severity. Furthermore, H2 addition can weaken the influence of oxygen deficiency on Mg explosion. Moreover, the explosion intensity of synthetic MgH2 was far stronger than that of

In this article, we review the mathematical foundations of convolutional neural nets (CNNs) with the goals of: (i) highlighting connections with techniques from statistics, signal processing, linear algebra, differential equations, and optimization, (ii) demystifying underlying computations, and (iii) identifying new types of applications. CNNs are powerful machine learning models that highlight features

ZnO deposition in porous γ‐Al2O3 via atomic layer deposition (ALD) is the critical first step for the fabrication of zeolitic imidazolate framework membranes using the ligand‐induced perm‐selectivation process (Science, 361 (2018), 1008–1011). A detailed computational fluid dynamics (CFD) model of the ALD reactor is developed using a finite‐volume‐based code and validated. It accounts for the transport

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.

Reinforcement learning (RL) is a data‐driven approach to synthesizing an optimal control policy. A barrier to wide implementation of RL‐based controllers is its data‐hungry nature during online training and its inability to extract useful information from human operator and historical process operation data. Here, we present a two‐step framework to resolve this challenge. First, we employ apprenticeship

Geometry‐dependency and plasticity are considered in the contact force models for the discrete element method simulations of elastic and elastoplastic fiber assemblies subject to uniaxial compression. It is observed that the contact force models have a significant impact on compressive loads. A simplified normal contact force model leads to smaller loads at large solid volume fractions compared to

Separation of aromatic organosulfur compounds is vital for upgrading the feed to clean fuel products, however, it remains a formidable challenge for the present adsorbents. Herein, a series of novel aerogel‐like boron carbon nitride (BCN) with three‐dimensional interconnected porous networks were fabricated via a hydrogel template and freeze‐casting strategy. The as‐prepared aerogel‐like BCN had a

Adsorptive removal of trace SO2 emissions from flue‐gases can significantly reduce energy and water consumption and minimize the amount of unmanageable waste, however, this remains a great challenge. Herein, we report a universal strategy of chemical immobilization of amino acids into a robust metal–organic framework to enhance deep desulfurization. The grafted amino acid resulted in the formation

This study presents conventional and artificial neural network‐based data‐driven modeling (DDM) methods to model simultaneously the filtered mesoscale drag, heat transfer and reaction rate in gas–particle flows. The dataset used for developing the DDM is filtered from highly resolved simulations closed by our recently formulated microscopic drag and heat transfer coefficients (HTCs). Results reveal

In this work, methods based upon nonequilibrium thermodynamics are elucidated to predict stationary states of chemical reactions in nonequilibrium plasma, and limits for energy conversion efficiency. CO2 splitting is used as an example reaction. Expectations from the theoretical framework are compared to experimental results, and reasonable agreement is obtained. The key conclusion is that the probability