This article proposes a novel distributionally robust optimization (DRO)‐based soft‐constrained model predictive control (MPC) framework to explicitly hedge against unknown external input terms in a linear state‐space system. Without a priori knowledge of the exact uncertainty distribution, this framework works with a lifted ambiguity set constructed using machine learning to incorporate the first‐order

The extraction of lanthanides from aqueous nitrate solutions by quaternary ammonium nitrate ionic liquids (e.g., [A336][NO3]) shows a negative sequence (i.e., light lanthanides are more efficiently extracted than heavy lanthanides), which conflicts with the lanthanide contraction. In this study, we explored the origin of the negative sequence by investigating the extraction of lanthanides from ethylammonium

A new 750 cm3 pilot test rig based on the “isochoric pressure method” was designed and commissioned for the hydrate measurements to concentrate sucrose solutions. The reactor included an improved agitation system and enabled sampling of the sucrose solutions. The experimental method was validated be performing dissociation measurements for the CO2 + water system. Gas hydrate kinetic and sampling data

Synthesis of adipic acid (AA) through the oxidation of cyclohexanol and cyclohexanone (K/A oil) with nitric acid was conducted in a capillary microreactor system. Effects of the temperature, the nitric acid concentration, the volumetric flow rate ratio of nitric acid to K/A oil, and the capillary length on the selectivity and the product yield were investigated systematically to achieve optimal reaction

The use of bismuth‐based catalysts is promising for formate production by the electroreduction of CO2 captured from waste streams. However, compared to the extensive research on catalysts, only a few studies have focused on electrochemical reactor performance. Hence, this work studied a continuous‐mode gas–liquid–solid reaction system for investigating CO2 electroreduction to formate using Bi‐catalyst‐coated

Gas hydrates have been endowed with great potential as the medium for natural gas storage & transportation. In this work, we prepared novel nanopromoters by grafting hydrophilic groups (SO3−, COO− and N[CH3]3+) covalently on polystyrene nanospheres (Group@PSNS), and for the first time achieved rapid formation of methane hydrates together compact agglomeration by regulating the hydrophilic groups

BaxSr1‐xCo0.8Fe0.2O3‐δ (BSCF) materials with different Ba doping amounts are widely applied as membranes for oxygen separation and electrodes in solid oxide cells. Different opinions were put forward about the effect of Ba contents on the oxygen transport kinetics. In this work, an oxygen permeation model was first used to investigate the effect of Ba content in BSCF (x = 0, 0.1, 0.3, 0.5, 0.7) on

We propose a new reinforcement learning approach for nonlinear optimal control where the value function is updated as restricted to control Lyapunov function (CLF) and the policy is improved using a variation of Sontag's formula. The practical asymptotic stability of the closed‐loop system is guaranteed during the training and at the end of training without requiring an additional actor network and

We present an image analysis algorithm for flocculation quality estimation in high‐solids slurries, and demonstrate its performance using inline process images of oil sands tailings flocculation. While a skilled human operator can often successfully evaluate such images, variations in feed as well as the lack of isolated flocs or spatial reference‐points inherent in a high‐solids slurry can cause conventional

SAPO‐34 hollow fiber zeolite membranes are successfully synthesized on α‐Al2O3 hollow fiber ceramic substrates by secondary growth method, and used to separate H2 from a binary mixture (H2, C3H8) or ternary mixture (H2, C3H8, and C3H6) under a wide temperature range (25–600°C) with the aim of using them for propane dehydrogenation (PDH) reactions at high temperature. The results show excellent performance

The high fractional free volume (FFV) endowed polymers of intrinsic microporosity (PIMs) with high gas permeability but low selectivity. Herein, an intermediate temperature range was deliberately utilized to tune PIM‐1 membrane microstructure in nitrogen atmosphere to enhance gas separation performance. During intermediate thermal manipulation, the synergistic effects of thermal‐induced cross‐linking

Fluids adsorbing in nanoporous solids cause high solvation pressures that deform the solids and affect properties of the fluids themselves. We calculate solvation pressure of nitrogen adsorbed at 77.4 K in spherical silica mesopores using two methods: macroscopic Derjaguin‐Broekhoff‐de Boer theory and molecular simulations. We show that both approaches give consistent results and the observed pressures

Predicting long‐term production from gas shale reservoirs is a challenging task due to changes in effective stress and permeability during gas production. Unlike coal, the variation of sorbing gas permeability with pore pressure in shale does not always feature a biphasic trend under a constant confining pressure. The present contribution demonstrates that the biphasic dependence of permeability on

Measuring the growth rate of non‐model anaerobic microbes typically requires the use of time‐consuming and often destructive manual measurements. Here, an Arduino based Automatic Pressure Evaluation System (A‐APES) was developed to automatically measure the rate of fermentation gas production as a proxy for microbial growth in anaerobic systems. The A‐APES system measures accumulated gas pressure in

In technical problems there is often the need to simultaneously describe both non‐stationary evaporation and non‐stationary crystallization of droplets and films. Poor wettability of the wall and high heat fluxes lead to the film rupture and the formation of pools, dry spots, droplets. To date, there are no well‐developed methods for calculating crystallization and evaporation in the presence of the

Exceptionally stable, mechanically robust, and highly methanol‐selective organosilica membranes, including Bis(triethoxysiyl)acetylene (BTESA), fluorine‐doped bis(triethoxysiyl) methane (F‐BTESM), and Cetyltrimethylammonium chloride‐etched bis(trimethoxysiyl)hexane (CTAC‐BTMSH), were prepared and utilized for organic solvent reverse osmosis (OSRO) separations. The BTESA membrane showed optimal separation

A pore network model is built to predict pressure drop in packed beds of arbitrary‐shaped particles, using a method that consists of particle packing by the rigid body technique, pore network construction by the maximal sphere algorithm, and numerical calculation of fluid flow. The pore network model is firstly validated by comparing with experiments, Ergun‐type equations, and particle‐resolved computational

Agitated‐pulsed column (APC) is a newly designed extraction column with excellent mass transfer performance. In this work, Sauter mean drop diameter d 32 and drop size distribution was investigated under different operation conditions in a 25 mm diameter APC. The results show that with an increase in pulsation intensity and agitation speed the drop size distribution is narrowed and d 32 is decreased

This paper addresses the problem of missing process data in data‐driven dynamic modeling approaches. The key motivation is to avoid using imputation methods or deletion of key process information when identifying the model, and utilizing the rest of the information appropriately at the model building stage. To this end, a novel approach is developed that adapts nonlinear iterative partial least squares

This study presents a first of its kind demonstration of successful enhancement of CO2 chemical absorption, under selected conditions, using a process intensification approach. A multifunctional device that integrates contact of phases and heat exchange has been developed, characterized, and tested. Heat transfer analysis has demonstrated the efficacy of the device as a heat exchanger, and mass transfer

In this investigation, CO2 capture performance of zeolite 13X monoliths with 600 and 800 cpsi in presence of SO2/NO impurities under dry and humid conditions were evaluated and compared with that of 13X beads. Dynamic breakthrough tests demonstrated a drastic reduction in CO2 capture capacity and deterioration of kinetics under dry‐clean conditions, whereas, upon switching the feed from a clean gas

Slug bubbling in single deck flat sheet MBRs (FSMBR) is effective in controlling membrane fouling. Here the primary focus is on the employment of the slug bubbling method, with its more economical air consumption, to a double‐deck large‐scale FSMBR with 100 membrane plates on each deck. The analysis of a new design concept shows that sufficient hydrodynamic effect could be induced by a novel economical

The flow characteristics of the blade unit of a tridimensional rotational flow sieve tray were investigated. First, the flow patterns are defined under different liquid arrangement methods. They are bilateral film flow, continuous perforated flow, and dispersion‐mixing flow in overflow distribution, film and jet flow and jet and mixed flow in spray distribution. Second, the time and frequency domain

Experimental and model‐based studies of acrylonitrile biohydration catalyzed by free cells were conducted in this work. The high ratios of the two phases of the reaction system and the effects of inhibition and inactivation on the enzyme make the process complicated; thus, its exact kinetics have never been reported. To fully understand and model the reaction, a microstructured chemical system was

Glucose solutions are commonly heated before use in medical and biotech applications to maintain cleanliness, however the resulting degradants can be toxic. This study examines two approaches to evaluating the heat degradants resulting from holding a 40% glucose solution at 55°C for five weeks: first, chemical changes to the solution were identified and quantified via analytical testing, and second

A new analytical fundamental equation of state (EOS) is presented for fluids. The equation is explicit in the effective molecular potentials and allows calculation of all thermodynamic properties over the whole fluid surface (gas, liquid, supercritical and gas–liquid phase transition). Outside the critical area (± 0.05T c), it is valid in a vast range of temperature and pressure (0.8T c to 7.5T c and

Enzyme immobilization enhances the catalytic activity and stability of the enzyme, and also improves reusability. Metal–organic frameworks (MOFs), which possess diversified structures and porosity, have been used as excellent carriers for enzyme immobilization. Pseudomonas fluorescens lipase (PFL) has been successfully immobilized onto MOFs by covalent cross‐linking to obtain a series of immobilized

The 2D top view of the droplet formation in microfluidic T‐junction devices with a neck is recorded to estimate the droplet volume under different flow conditions. The channel with a neck at the T‐junction, to provide a narrow structure, is proposed but has not been analyzed as the normal T‐junction. The droplet generation process is separated into two stages, including the filling stage and the squeezing

For detailed simulation and evaluation of stirred extraction columns a CFD based compartment‐model was developed. Instead of simulating all effects in a computational expensive PBE‐CFD‐model, the velocity field calculation of the continuous phase is decoupled from the calculation of the dispersed phase (one‐way coupling). In CFD only the continuous phase is simulated and the resulting velocity profile

We study the evaporation dynamics of multiple water droplets deposited in ordered arrays or randomly distributed (sprayed) on superhydrophobic substrates (SHP) and smooth silicon wafers (SW). The evaluation of mass of the droplets as a function of time shows a power‐law behavior with exponent 3/2, and from the prefactor of the power‐law an evaporation rate can be determined. We find that the evaporation

Rational synthesis of highly dispersed and active metal nanoparticles (NP) for application in catalysis has been a hot but challenging research topic. Herein, we report a facile strategy for dispersing and stabilizing noble metal NP in a reducible metal oxide support (e.g., TiO2) through engineering oxygen vacancies and their anchoring effect. The pre‐reduction of TiO2 support produces oxygen vacancies

Selectively separating CH4 from N2 in coal‐mine methane is significantly important in the chemical industry, but challenging and energy‐intensive. Using porous materials as adsorbents can separate CH4/N2 mixtures with low energy consumption, but most adsorbents encounter the problem of poor separation selectivity. Here, we propose a strategy for improving CH4/N2 selectivity by controlling pore wall

Droplet evaporative crystallization on microscale heterogeneous surface is a vivid topic in chemical engineering, bioengineering, nanomaterials, and so on. Here, 3D printed interfacial matrix platform with regular pillar convexity and tunnel structure is fabricated to reveal the mechanism of the interfacial micro droplet crystallization. Element‐based rotation volume model is established to simulate

We investigated the flow characteristics in a tank of H /T = 1.5 stirred by a novel multi‐blade combined agitator (MBC) by using time‐resolved particle image velocimetry and large eddy simulation approach. The predictions were assessed by Y + values, Taylor microscale and power spectrum analysis, as well as experimental validation of velocity distributions. Results demonstrate that the MBC agitator

Charged clay surfaces can impact the storage and mobility of hydrocarbon and water mixtures. Here, we use equilibrium molecular dynamics (MD) and nonequilibrium MD simulations to investigate hydrocarbon‐water mixtures and their transport in slit‐shaped illite nanopores. We construct two illite pore models with different surface chemistries: potassium–hydroxyl (PH) and hydroxyl–hydroxyl (HH) structures

Multiple breakdown phenomena may take place when operating dielectric elastomers. Thermal breakdown, which occurs due to Joule heating, becomes of special importance when using multilayered stacks of dielectric elastomers, due to the large volume‐to‐surface‐area‐ratio. In this article, a 2D axisymmetric finite‐element model of a multilayered stack of dielectric elastomers is set up in COMSOL Multiphysics®

Droplet impingement and anisotropic wetting on chemically heterogeneous stripe‐patterned surfaces is simulated by means of many‐body dissipative particle dynamics. The ratio of the stripe width and initial droplet diameter, defined as β , ranges from 0.5 to 1.0 so that the wetting process is in the Beyond–Cassie–Baxter regime and is highly anisotropic. At zero Weber number (that is, without considering

Recent increases in renewable power generation challenge the operation of the power grid: generation rates fluctuate in time and are not synchronized with power demand fluctuations. Demand response (DR) consists of adjusting user electricity demand in order to balance available power supply. Chemical plants are appealing candidates for DR programs; they offer large, concentrated loads that can be modulated

Understanding flame propagation mechanism and thermal behavior of flammable dusts is of crucial importance, since they strongly affect the flammability and explosion parameters. In a previous work, we found that the volatile point of anthraquinone/nicotinic acid mixtures can be lower than the one of the pure dusts, suggesting a synergistic effect. In this work, thermogravimetric and differential scanning

Models for gas separations with spiral‐wound membranes are developed and found to exhibit good agreement with experiments performed on N2/O2 mixtures. The two‐dimensional (2D) model can be accurately approximated by a one‐dimensional (1D) surrogate model when the spacer widths are chosen to make the channel pressure drops small. Subsequently, the separation of propane/propylene mixtures from the recycle

Due to the complexity of the screen‐printing operation and the rheological behaviors of the screen‐printable paste, such a paste is usually formulated by trial‐and‐error. In this report, a systematic procedure, based on heuristics and mechanistic models, for the design of a screen‐printable paste is developed. The procedure is demonstrated by a case study of the formulation of a conductive paste of

A respirometric method for the kinetic modeling of ammonium‐oxidizing bacteria (AOB) and nitrite‐oxidizing bacteria (NOB) was implemented in two membrane bioreactor (MBRA and MBRB) systems. These biological systems worked at mixed liquor suspended solids concentration of about 6.6 g L−1. MBRA worked at 6 hr of hydraulic retention time (HRT) and 20.7°C, while the operational conditions for MBRB were

In order to provide basic data for the crystallization of dl ‐methionine and understand the thermodynamic properties of dissolution, the solubility of dl ‐methionine in water was measured by gravimetric method from 294.05 to 347.05 K and the solubility at different pH values under temperature 302.95 to 342.05 K was determined by elemental analysis in this work. The experimental data show that the solubility

The rheology of non‐Newtonian slurries is measured in a recirculating pipe loop using an acoustic velocimetry‐pressure drop technique at very low flow rates and variable solids loadings. The technique avoids (a) settling at low solids concentration, a shortcoming of bench rheometry, by using a vertical test section, and (b) physical sampling, providing greater safety. Speed of sound in the suspensions

Zeolites have been widely used for the processes of adsorption, separation, and catalysis, which are strongly correlated with molecular diffusion. However, the correlation between pore dimension and diffusion properties has not been systematically investigated so far. In this work, the diffusion properties of alkanes in six zeolites with similar pore sizes but different pore dimension have been examined

Solvent mass transfer plays a key role in a thermal gravity drainage process involving solvent. The diffusion coefficients of solvent in such a process are not well studied. This article presents the effective diffusion coefficients of solvent in bitumen‐saturated sands under high temperature/pressure conditions measured using a CT scanning technique. Experimental results show that the effective diffusion

The vapor split ratio (RV) adjustment plays an important role on energy efficiency during dividing wall column (DWC) operation. In order to achieve active control of R V, this aticle presents an innovative vapor splitter driven by hydraulics. The vapor flows into main tower from prefractionation section through the rectangle hole located at the end of the partition. Vapor splitting is implemented by

This article introduces the concept of minimal structure (MSTR) and presents an enumeration algorithm for the synthesis of heat exchanger networks based on MSTR. Minimal Structures refer to a class of heat exchanger networks featuring acyclic heat transfer networks without energy loops. The enumerations used are either exhaustive or smart with a stopping criterion. Without loss of generality we use

Interfacial tension is an essential physical property in two‐phase flow, and it changes due to the mass transfer. The measurement of dynamic interfacial tension (DIFT) in such a condition is a difficult problem. In the previous study (Zhou et al., Chem Eng Sci. 2019; 197:172–183), we presented the quantitative relation between the droplet breakup frequency function (DBFF) and interfacial tension. It

Cyclic distillation is an emerging process intensification technology, which can improve separation efficiency compared to conventional distillation. As most current models only account for the mass transfer, there is a lack of a stage model for cyclic distillation processes, which includes considerations of both mass and energy transfer. Such a model is presented in this article, and using this model

In Part I of this work, the synthesis of minimal heat exchanger networks using the isothermal mixing stage‐wise superstructure was presented. In this Part II, an extension of the algorithm presented in Part I is made to consider networks that allow multiple solutions regarding heat allocation, that is, they have energy loops where heat loads can be rearranged without changing the overall energy consumption

The aim of this study is to evaluate the performance of multilevel Monte Carlo (MLMC) sampling technique for uncertainty quantification in stochastic multiscale systems. Two systems, a chemical vapor deposition chamber and a catalytic flow reactor, subject to multiple parameter uncertainty, were considered. The distributions of the systems' observables were estimated using standard MC sampling and

Spherical dimples in cylindrical tubes enhance heat transfer and lead to a more uniform radial temperature profile. To combine these positive properties with a low pressure drop, a single dimple was optimized through a genetic algorithm. Multiple design parameters such as width, height, and curvature of the dimple were investigated. Heart‐shaped dimples outperformed spherical dimples. Three‐dimensional

In this work, an automatic liquid–liquidtwo‐phase flow pattern recognition platform was developed to help circumvent the difficulties in labor‐intensive hydrodynamics studies. Trained by about 30,000 of human‐labeled flow pattern images, a convolutional neural network was built with the expert‐level ability in the flow pattern recognition tasks and then coupled with automatic pump feeding system and

This study is aimed at unveiling the influence of binary mixtures of nonspherical particles on hopper discharge behavior, which remains poorly understood. The discrete element method (DEM) is employed to simulate seven particle types with aspect ratios between 0 and 2 (namely, a sphere, two ellipsoids, two cylinders, and two cuboids) with the same volume. Seven monodisperse systems and twelve binary‐shape

The emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH3 due to their unique properties. However, the solid or highly viscous ILs are not suitable for traditional scrubbing. Therefore, an effective strategy was proposed by combining the protic ILs (PILs) with acidic H and low viscous ethylene glycol (EG) to form IL‐based deep eutectic solvents (DESs)

Precombustion carbon capture is an effective strategy to reduce large‐scale CO2 emissions, which is mainly used in the area of integrated gasification combined cycle (IGCC) power plants. Oxygen transport membranes (OTMs) were suggested as the air separation unit to produce high purity oxygen for the gasifier. However, the improvement in efficiency was limited. Here, a new IGCC process is reported based

The article introduces a detailed model for carbohydrate chemistry in kraft pulping. This article is continuation to the modeling work carried out for hot water extraction and chemical pulp bleaching. The model includes galactoglucomannan, xylan, and cellulose acid–base equilibria, in addition to peeling, stopping, and alkaline hydrolysis reactions of the same carbohydrates, as well as hexenuronic

Model reduction of a high‐dimensional distributed parameter system (DPS) reduces the complexity of the system for various applications, from monitoring to model predictive control, while retaining its intrinsic properties. Unfortunately, the assumption of time–space separability usually fails to hold for popular time–space separation model reduction methods because the space and time of the DPS are

Three types of self‐prepared chemical dust suppressants (CDSs) were investigated for their inhibitory effects on nitrocellulose (NC) cloud dust explosion. The results revealed that NC is extremely sensitive to electric sparks and has a high explosion intensity. CaCl2‐CDS effectively increased the particle size to control fly dust substantially inhibiting dust cloud explosions. However, both Na2SO4‐CDS